diff --git a/kernel/trunk/runtests.py b/kernel/trunk/runtests.py
index 86b4d1bd8e..b836e9b25e 100755
--- a/kernel/trunk/runtests.py
+++ b/kernel/trunk/runtests.py
@@ -172,7 +172,7 @@ def run_tests_serially(tests, root_dir):
     return thread
 
 def gcc(fin, fout):
-    flags = "-m32 -std=c11 -g -O0 -fno-pie -w" # -masm-intel
+    flags = "-m32 -std=c11 -g -O0 -fno-pie -w"
     defines = "-D_FILE_OFFSET_BITS=64 -DNDEBUG -D_POSIX_C_SOURCE=200809L"
     include = "-Iumka -Iumka/linux"
     command = f"clang {flags} {defines} {include} -c {fin} -o {fout}"
@@ -185,8 +185,13 @@ def build_umka_asm():
     files = "umka/umka.asm umka/build/umka.o -s umka/build/umka.fas"
     memory = "-m 2000000"
     command = f"{include} fasm {flags} {files} {memory}"
-    print(command)
-    os.system(command)
+    if sys.platform != "win32":
+        print(command)
+        os.system(command)
+    else:
+        my_env = os.environ.copy()
+        my_env["INCLUDE"] = "../../programs/develop/libraries/libcrash/hash"
+        print(subprocess.check_output(f"fasm {flags} {files} {memory} -dwin32=1", shell = True, env = my_env))
 
 def build_umka():
     if not enable_umka:
@@ -194,12 +199,16 @@ def build_umka():
     if os.path.exists("umka_shell.exe"):
         return
     os.makedirs("umka/build/linux", exist_ok = True)
+    os.makedirs("umka/build/win32", exist_ok = True)
     sources = [ "umka_shell.c", 
                 "shell.c",
                 "vdisk.c",
                 "lodepng.c",
-                "linux/pci.c",
-                "linux/thread.c" ]
+                "getopt.c" ]
+    if sys.platform == "win32":
+        sources += [ "win32/pci.c", "win32/thread.c" ]
+    else:
+        sources += [ "linux/pci.c", "linux/thread.c" ]
     sources = [f"umka/{f}" for f in sources]
     objects = []
     for source in sources:
@@ -210,9 +219,16 @@ def build_umka():
     build_umka_asm()
     objects.append("umka/build/umka.o")
     objects = " ".join(objects)
-    command = f"gcc -m32 -no-pie -o umka_shell.exe -static -T umka/umka.ld {objects}"
+    if sys.platform != "win32":
+        ld_script = "-T umka/umka.ld"
+    else:
+        ld_script = ""
+    command = f"clang -m32 -fno-pie -o umka_shell.exe -static {ld_script} {objects}"
     print(command)
     os.system(command)
+    if not os.path.exists("umka_shell.exe"):
+        print("Could't compile umka_shell.exe")
+        exit()
 
 def create_relocated(root_dir, fname):
     with open(fname, "rb") as f:
@@ -227,8 +243,18 @@ def create_relocated(root_dir, fname):
 def run_umka_test(root_dir, test_file_path):
     test = create_relocated(root_dir, test_file_path)
     ref_log = create_relocated(root_dir, f"{test_file_path[:-2]}.ref.log")
-    out_log = f"{test_file_path[:-2]}.out.log.o"
-    os.system(f"./umka_shell.exe < {test} > {out_log}")
+    out_log = f"{test_file_path[:-2]}.out.log"
+    if sys.platform != "win32":
+        prefix = "./"
+    else:
+        prefix = ""
+    os.system(f"{prefix}umka_shell.exe < {test} > {out_log}")
+    if sys.platform == "win32":
+        with open(out_log, "rb") as f:
+            contents = f.read()
+        contents_no_crlf = contents.replace(b"\r\n", b"\n")
+        with open(out_log, "wb") as f:
+            f.write(contents_no_crlf)
     if not filecmp.cmp(ref_log, out_log):
         print(f"FAILURE: {test_file_path}\n", end = "")
     else:
diff --git a/kernel/trunk/test/common/__init__.py b/kernel/trunk/test/common/__init__.py
index 004c86062c..1b2455e44d 100644
--- a/kernel/trunk/test/common/__init__.py
+++ b/kernel/trunk/test/common/__init__.py
@@ -89,7 +89,8 @@ def get_file_directory(path):
 
 def run_qemu(root_dir, test_dir, debug_log):
     # Make local copy of IMG, so we will be able to run the test in parallel
-    os.remove(f"{test_dir}/kolibri_test.img") # If previous test run interrupted the file may be busy
+    if os.path.exists(f"{test_dir}/kolibri_test.img"): # If previous test run interrupted the file may be busy
+        os.remove(f"{test_dir}/kolibri_test.img")
     shutil.copyfile(f"{root_dir}/kolibri_test.img", f"{test_dir}/kolibri_test.img")
     qemu_command = f"qemu-system-i386"
     flags = ""
diff --git a/kernel/trunk/umka/shell.c b/kernel/trunk/umka/shell.c
index 33388c0371..0ef6c93f25 100644
--- a/kernel/trunk/umka/shell.c
+++ b/kernel/trunk/umka/shell.c
@@ -307,7 +307,7 @@ shell_ramdisk_init(int argc, char **argv) {
         return;
     }
     const char *fname = argv[1];
-    FILE *f = fopen(fname, "r");
+    FILE *f = fopen(fname, "rb");
     if (!f) {
         fprintf(fout, "[!] can't open file '%s': %s\n", fname, strerror(errno));
         return;
@@ -1093,7 +1093,7 @@ shell_put_image(int argc, char **argv) {
         fputs(usage, fout);
         return;
     }
-    FILE *f = fopen(argv[1], "r");
+    FILE *f = fopen(argv[1], "rb");
     fseek(f, 0, SEEK_END);
     size_t fsize = ftell(f);
     rewind(f);
@@ -1126,7 +1126,7 @@ shell_put_image_palette(int argc, char **argv) {
         fputs(usage, fout);
         return;
     }
-    FILE *f = fopen(argv[1], "r");
+    FILE *f = fopen(argv[1], "rb");
     fseek(f, 0, SEEK_END);
     size_t fsize = ftell(f);
     rewind(f);
@@ -1332,7 +1332,7 @@ shell_blit_bitmap(int argc, char **argv) {
         return;
     }
     const char *fname = argv[1];
-    FILE *f = fopen(fname, "r");
+    FILE *f = fopen(fname, "rb");
     if (!f) {
         fprintf(fout, "[!] can't open file '%s': %s\n", fname, strerror(errno));
         return;
@@ -1763,7 +1763,7 @@ shell_acpi_preload_table(int argc, char **argv) {
         fputs(usage, fout);
         return;
     }
-    FILE *f = fopen(argv[1], "r");
+    FILE *f = fopen(argv[1], "rb");
     if (!f) {
         fprintf(fout, "[umka] can't open file: %s\n", argv[1]);
         return;
@@ -1780,30 +1780,6 @@ shell_acpi_preload_table(int argc, char **argv) {
     kos_acpi_ssdt_cnt++;
 }
 
-static void
-shell_pci_set_path(int argc, char **argv) {
-    const char *usage = \
-        "usage: pci_set_path <path>\n"
-        "  path           where aaaa:bb:cc.d dirs are";
-    if (argc != 2) {
-        fputs(usage, fout);
-        return;
-    }
-    strcpy(pci_path, argv[1]);
-}
-
-static void
-shell_pci_get_path(int argc, char **argv) {
-    (void)argv;
-    const char *usage = \
-        "usage: pci_get_path";
-    if (argc != 1) {
-        fputs(usage, fout);
-        return;
-    }
-    fprintf(fout, "pci path: %s\n", pci_path);
-}
-
 static void
 shell_bg_set_size(int argc, char **argv) {
     const char *usage = \
@@ -1869,7 +1845,7 @@ shell_bg_put_img(int argc, char **argv) {
         fputs(usage, fout);
         return;
     }
-    FILE *f = fopen(argv[1], "r");
+    FILE *f = fopen(argv[1], "rb");
     fseek(f, 0, SEEK_END);
     size_t fsize = ftell(f);
     rewind(f);
@@ -1949,8 +1925,6 @@ func_table_t shell_cmds[] = {
     { "ls80",                    shell_ls80 },
     { "move_window",             shell_move_window },
     { "mouse_move",              shell_mouse_move },
-    { "pci_get_path",            shell_pci_get_path },
-    { "pci_set_path",            shell_pci_set_path },
     { "process_info",            shell_process_info },
     { "put_image",               shell_put_image },
     { "put_image_palette",       shell_put_image_palette },
diff --git a/kernel/trunk/umka/umka.asm b/kernel/trunk/umka/umka.asm
index 76c054daac..ce3da048ab 100644
--- a/kernel/trunk/umka/umka.asm
+++ b/kernel/trunk/umka/umka.asm
@@ -1,6 +1,36 @@
 ; TODO: SPDX
 
-format ELF
+if ~ defined win32
+    format ELF
+else
+    format MS COFF
+
+    macro c_public name, _alias, _argsize {
+        if ~ _argsize eq nomangle
+            if _alias eqtype 'string'
+                if _argsize eqtype 1
+                    public name as '_' # _alias # '@' # `_argsize
+                else
+                    public name as '_' # _alias
+                end if
+            else if _alias eqtype 1
+                public name as '_' # `name # '@' # `_alias
+            else
+                public name as '_' # `name
+            end if
+        else
+            public name as _alias
+        end if
+    }
+
+    macro extrn name, _argsize {
+        if _argsize eqtype 1
+            extrn '_' # `name # '@' # `_argsize as name
+        else
+            extrn '_' # `name as name
+        end if
+    }
+end if
 
 __DEBUG__ = 1
 __DEBUG_LEVEL__ = 1
@@ -11,73 +41,73 @@ UMKA_OS    = 3
 
 UMKA_MEMORY_BYTES = 256 SHL 20
 
-public umka_sys_put_image_palette
-public disk_add
-public disk_del
-public disk_list
-public disk_media_changed
+c_public umka_sys_put_image_palette
+c_public disk_add, 16
+c_public disk_del, 4
+c_public disk_list
+c_public disk_media_changed,8
 
-public xfs._.user_functions as 'xfs_user_functions'
-public ext_user_functions
-public fat_user_functions
-public ntfs_user_functions
+c_public xfs._.user_functions, 'xfs_user_functions'
+c_public ext_user_functions
+c_public fat_user_functions
+c_public ntfs_user_functions
 
-public i40
+c_public i40, 'i40', nomangle
 
-public coverage_begin
-public coverage_end
+c_public coverage_begin
+c_public coverage_end
 
-public sha3_256_oneshot as 'hash_oneshot'
-public kos_time_to_epoch
-public umka_init
+c_public sha3_256_oneshot, 'hash_oneshot'
+c_public kos_time_to_epoch
+c_public umka_init
 
-public current_process as 'kos_current_process'
-public current_slot as 'kos_current_slot'
-public current_slot_idx as 'kos_current_slot_idx'
+c_public current_process, 'kos_current_process'
+c_public current_slot, 'kos_current_slot'
+c_public current_slot_idx, 'kos_current_slot_idx'
 
-public thread_count as 'kos_thread_count'
-public TASK_TABLE as 'kos_task_table'
-public TASK_BASE as 'kos_task_base'
-public TASK_DATA as 'kos_task_data'
-public SLOT_BASE as 'kos_slot_base'
-public window_data as 'kos_window_data'
+c_public thread_count, 'kos_thread_count'
+c_public TASK_TABLE, 'kos_task_table'
+c_public TASK_BASE, 'kos_task_base'
+c_public TASK_DATA, 'kos_task_data'
+c_public SLOT_BASE, 'kos_slot_base'
+c_public window_data, 'kos_window_data'
 
-public WIN_STACK as 'kos_win_stack'
-public WIN_POS as 'kos_win_pos'
-public lfb_base as 'kos_lfb_base'
+c_public WIN_STACK, 'kos_win_stack'
+c_public WIN_POS, 'kos_win_pos'
+c_public lfb_base, 'kos_lfb_base'
 
-public RAMDISK as 'kos_ramdisk'
-public ramdisk_init as 'kos_ramdisk_init'
+c_public RAMDISK, 'kos_ramdisk'
+c_public ramdisk_init, 'kos_ramdisk_init'
 
-public acpi_ssdt_cnt as 'kos_acpi_ssdt_cnt'
-public acpi_ssdt_base as 'kos_acpi_ssdt_base'
-public acpi_ssdt_size as 'kos_acpi_ssdt_size'
+c_public acpi_ssdt_cnt, 'kos_acpi_ssdt_cnt'
+c_public acpi_ssdt_base, 'kos_acpi_ssdt_base'
+c_public acpi_ssdt_size, 'kos_acpi_ssdt_size'
 
-public stack_init as 'kos_stack_init'
-public net_add_device
+c_public stack_init, 'kos_stack_init'
+c_public net_add_device
 
-public draw_data
-public img_background
-public mem_BACKGROUND
-public sys_background
-public REDRAW_BACKGROUND as 'kos_redraw_background'
-public new_sys_threads as 'kos_new_sys_threads'
-public osloop as 'kos_osloop'
-public set_mouse_data as 'kos_set_mouse_data'
-public scheduler_current as 'kos_scheduler_current'
-public eth_input as 'kos_eth_input'
-public net_buff_alloc as 'kos_net_buff_alloc'
+c_public draw_data
+c_public img_background
+c_public mem_BACKGROUND
+c_public sys_background
+c_public REDRAW_BACKGROUND, 'kos_redraw_background'
+c_public new_sys_threads, 'kos_new_sys_threads', nomangle
+c_public osloop, 'kos_osloop'
+c_public set_mouse_data, 'kos_set_mouse_data', 20
+c_public scheduler_current, 'kos_scheduler_current'
+c_public eth_input, 'kos_eth_input'
+c_public net_buff_alloc, 'kos_net_buff_alloc'
 
-public mem_block_list
+c_public mem_block_list
 
-public acpi_dev_data as "kos_acpi_dev_data"
-public acpi_dev_size as "kos_acpi_dev_size"
-public kernel_alloc as "kos_kernel_alloc"
+c_public acpi_dev_data, "kos_acpi_dev_data"
+c_public acpi_dev_size, "kos_acpi_dev_size"
+c_public kernel_alloc, "kos_kernel_alloc"
 
-public window._.set_screen as 'kos_window_set_screen'
-public _display as 'kos_display'
+c_public window._.set_screen, 'kos_window_set_screen'
+c_public _display, 'kos_display'
 
-public BOOT as 'kos_boot'
+c_public BOOT, 'kos_boot'
 
 macro cli {
         pushfd
@@ -112,7 +142,7 @@ include 'macros.inc'
 macro diff16 msg,blah2,blah3 {
   if msg eq "end of .data segment"
 ; fasm doesn't align on 65536, but ld script does
-section '.bss.aligned65k' writeable align 65536
+section '.bss.65k' writeable align 512
 bss_base:
   end if
 }
@@ -505,7 +535,7 @@ proc umka_init c uses ebx esi edi ebp
         ret
 endp
 
-public skin_udata
+c_public skin_udata
 proc idle uses ebx esi edi
 .loop:
         mov     ecx, 10000000
@@ -517,7 +547,7 @@ proc idle uses ebx esi edi
         ret
 endp
 
-extrn pci_read
+extrn pci_read, 20
 proc pci_read_reg uses ebx esi edi
         mov     ecx, eax
         and     ecx, 3
@@ -541,6 +571,7 @@ endp
 proc sys_msg_board
         cmp     cl, 0x0d
         jz      @f
+if ~ defined win32
         pushad
         mov     eax, SYS_WRITE
         mov     ebx, STDOUT
@@ -550,6 +581,15 @@ proc sys_msg_board
         int     0x80
         pop     ecx
         popad
+else
+        extrn   putchar
+
+        pushad
+        push    ecx
+        call    putchar
+        add     esp, 4
+        popad
+end if
 @@:
         ret
 endp
@@ -559,13 +599,13 @@ proc delay_ms
         ret
 endp
 
-public umka_cli
+c_public umka_cli
 proc umka_cli
         cli     ; macro
         ret
 endp
 
-public umka_sti
+c_public umka_sti
 proc umka_sti
         sti     ; macro
         ret
@@ -593,7 +633,7 @@ endp
 
 extrn reset_procmask
 extrn get_fake_if
-public irq0
+c_public irq0
 proc irq0 c, _signo, _info, _context
         DEBUGF 2, "### irq0\n"
         pushfd
@@ -735,10 +775,10 @@ restore sys_msg_board,delay_ms
 coverage_end:
 
 ; fasm doesn't align on 65536, but ld script does
-section '.data.aligned65k' writeable align 65536
-public umka_tool
+section '.data' readable writeable align 512
+c_public umka_tool
 umka_tool dd ?
-public umka_initialized
+c_public umka_initialized
 umka_initialized dd 0
 fpu_owner dd ?
 
diff --git a/kernel/trunk/umka/umka.h b/kernel/trunk/umka/umka.h
index 81eb76b66b..99d26e09c8 100644
--- a/kernel/trunk/umka/umka.h
+++ b/kernel/trunk/umka/umka.h
@@ -9,6 +9,12 @@
 #define BDFE_LEN_CP866 304
 #define BDFE_LEN_UNICODE 560
 
+#if defined(WIN32) || defined(_WIN32)
+    typedef size_t off_t;
+    typedef long ssize_t;
+#   define PATH_MAX 256
+#endif
+
 typedef struct {
     uint32_t left, top, right, bottom;
 } rect_t;
diff --git a/kernel/trunk/umka/vdisk.c b/kernel/trunk/umka/vdisk.c
index 1af23a768a..b9ee16a351 100644
--- a/kernel/trunk/umka/vdisk.c
+++ b/kernel/trunk/umka/vdisk.c
@@ -21,9 +21,9 @@ void *vdisk_init(const char *fname, int adjust_cache_size, size_t cache_size) {
         printf("vdisk: can't open file '%s': %s\n", fname, strerror(errno));
         return NULL;
     }
-    fseeko(f, 0, SEEK_END);
-    off_t fsize = ftello(f);
-    fseeko(f, 0, SEEK_SET);
+    fseek(f, 0, SEEK_END);
+    off_t fsize = ftell(f);
+    fseek(f, 0, SEEK_SET);
     size_t sect_size = 512;
     if (strstr(fname, "s4096") != NULL || strstr(fname, "s4k") != NULL) {
         sect_size = 4096;
@@ -51,7 +51,7 @@ vdisk_read(void *userdata, void *buffer, off_t startsector,
                size_t *numsectors) {
     COVERAGE_OFF();
     vdisk_t *vdisk = userdata;
-    fseeko(vdisk->file, startsector * vdisk->sect_size, SEEK_SET);
+    fseek(vdisk->file, startsector * vdisk->sect_size, SEEK_SET);
     fread(buffer, *numsectors * vdisk->sect_size, 1, vdisk->file);
     COVERAGE_ON();
     return ERROR_SUCCESS;
@@ -62,7 +62,7 @@ vdisk_write(void *userdata, void *buffer, off_t startsector,
                 size_t *numsectors) {
     COVERAGE_OFF();
     vdisk_t *vdisk = userdata;
-    fseeko(vdisk->file, startsector * vdisk->sect_size, SEEK_SET);
+    fseek(vdisk->file, startsector * vdisk->sect_size, SEEK_SET);
     fwrite(buffer, *numsectors * vdisk->sect_size, 1, vdisk->file);
     COVERAGE_ON();
     return ERROR_SUCCESS;
diff --git a/kernel/trunk/umka/win32/pci.c b/kernel/trunk/umka/win32/pci.c
new file mode 100644
index 0000000000..eea19aff20
--- /dev/null
+++ b/kernel/trunk/umka/win32/pci.c
@@ -0,0 +1,8 @@
+#include "pci.h"
+
+__attribute__((stdcall)) uint32_t pci_read(uint32_t bus, uint32_t dev,
+                                           uint32_t fun, uint32_t offset,
+                                           size_t len) {
+	printf("STUB: %s() -> 0", __func__);
+    return 0;
+}
diff --git a/kernel/trunk/umka/win32/pci.h b/kernel/trunk/umka/win32/pci.h
new file mode 100644
index 0000000000..454a44c8ec
--- /dev/null
+++ b/kernel/trunk/umka/win32/pci.h
@@ -0,0 +1,8 @@
+#ifndef PCI_H_INCLUDED
+#define PCI_H_INCLUDED
+
+#include "umka.h"
+
+extern char pci_path[PATH_MAX];
+
+#endif  // PCI_H_INCLUDED
diff --git a/kernel/trunk/umka/win32/thread.c b/kernel/trunk/umka/win32/thread.c
new file mode 100644
index 0000000000..ef28c95407
--- /dev/null
+++ b/kernel/trunk/umka/win32/thread.c
@@ -0,0 +1,8 @@
+void reset_procmask(void) {
+	printf("STUB: %s()", __func__);
+}
+
+int get_fake_if(void *ctx) {
+	printf("STUB: %s() -> 0", __func__);
+	return 0;
+}