diff --git a/bochs/config.cc b/bochs/config.cc
index 6fa81c146..f57ab2bf3 100644
--- a/bochs/config.cc
+++ b/bochs/config.cc
@@ -128,7 +128,7 @@ static Bit64s bx_param_handler(bx_param_c *param, bool set, Bit64s val)
           val = get_floppy_type_from_image(SIM->get_param_string("path", base)->getptr());
           SIM->get_param_enum("type", base)->set(val);
         } else if (!SIM->get_init_done() && (val != BX_FLOPPY_NONE)) {
-          device = get_floppy_devtype_from_type(val);
+          device = get_floppy_devtype_from_type((int)val);
           SIM->get_param_enum("devtype", base)->set(device);
         }
       }
@@ -2361,7 +2361,7 @@ int bx_split_option_list(const char *msg, const char *rawopt, char **argv, int m
       strcpy(tmpstr, ptr);
       ptr2 = tmpstr;
       while (isspace(*ptr2)) ptr2++;
-      i = strlen(ptr2) - 1;
+      i = (int)strlen(ptr2) - 1;
       while ((i >= 0) && isspace(ptr2[i])) {
         ptr2[i] = 0;
         i--;
@@ -3029,7 +3029,7 @@ static int parse_line_formatted(const char *context, int num_params, char *param
                      &tm_time.tm_hour, &tm_time.tm_min, &tm_time.tm_sec, &year);
           if ((n == 7) && (year >= 1980) && (strstr(months, mon) != NULL)) {
             tm_time.tm_year = year - 1900;
-            tm_time.tm_mon = 12 - (strlen(strstr(months, mon)) / 4);
+            tm_time.tm_mon = 12 - ((int)strlen(strstr(months, mon)) / 4);
             SIM->get_param_num(BXPN_CLOCK_TIME0)->set(mktime(&tm_time));
           } else {
             PARSE_ERR(("%s: time0 string format malformed.", context));
diff --git a/bochs/config.h.in b/bochs/config.h.in
index 73883bd13..4dee8c0a5 100644
--- a/bochs/config.h.in
+++ b/bochs/config.h.in
@@ -85,6 +85,15 @@
 #define BX_SHOW_IPS         0
 
 
+#define MSVC_TARGET 0
+#if defined(_MSC_VER) && defined(MSVC_TARGET)
+#if defined(_M_X64) && (MSVC_TARGET != 64)
+#error Bochs not configured for MSVC WIN64
+#elif !defined(_M_X64) && (MSVC_TARGET != 32)
+#error Bochs not configured for MSVC WIN32
+#endif
+#endif
+
 #if (BX_SHOW_IPS) && (defined(__MINGW32__) || defined(_MSC_VER))
 #define        SIGALRM         14
 #endif
diff --git a/bochs/configure.in b/bochs/configure.in
index 4e71e78ee..3595ce45c 100644
--- a/bochs/configure.in
+++ b/bochs/configure.in
@@ -48,9 +48,11 @@ case "$target" in
     case "$target" in
       x86_64*)
         MSVC_TARGET=64
+        AC_DEFINE(MSVC_TARGET, 64)
         ;;
       *)
         MSVC_TARGET=32
+        AC_DEFINE(MSVC_TARGET, 32)
         ;;
     esac
     ;;
diff --git a/bochs/iodev/network/e1000.cc b/bochs/iodev/network/e1000.cc
index f71f31ab4..0e59fd854 100644
--- a/bochs/iodev/network/e1000.cc
+++ b/bochs/iodev/network/e1000.cc
@@ -1503,7 +1503,7 @@ void bx_e1000_c::rx_frame(const void *buf, unsigned buf_size)
         if (copy_size > BX_E1000_THIS s.rxbuf_size) {
           copy_size = BX_E1000_THIS s.rxbuf_size;
         }
-        DEV_MEM_WRITE_PHYSICAL_DMA(le64_to_cpu(desc.buffer_addr), copy_size,
+        DEV_MEM_WRITE_PHYSICAL_DMA(le64_to_cpu(desc.buffer_addr), (unsigned)copy_size,
                                    (Bit8u *)buf + desc_offset + vlan_offset);
       }
       desc_offset += desc_size;
diff --git a/bochs/iodev/pci_ide.cc b/bochs/iodev/pci_ide.cc
index ffc097ed7..d4df1d286 100644
--- a/bochs/iodev/pci_ide.cc
+++ b/bochs/iodev/pci_ide.cc
@@ -267,7 +267,7 @@ void bx_pci_ide_c::timer()
   }
   if (BX_PIDE_THIS s.bmdma[channel].cmd_rwcon) {
     BX_DEBUG(("READ DMA to addr=0x%08x, size=0x%08x", prd.addr, size));
-    count = size - (BX_PIDE_THIS s.bmdma[channel].buffer_top - BX_PIDE_THIS s.bmdma[channel].buffer_idx);
+    count = (int)(size - (BX_PIDE_THIS s.bmdma[channel].buffer_top - BX_PIDE_THIS s.bmdma[channel].buffer_idx));
     while (count > 0) {
       sector_size = count;
       if (DEV_hd_bmdma_read_sector(channel, BX_PIDE_THIS s.bmdma[channel].buffer_top, &sector_size)) {
@@ -288,7 +288,7 @@ void bx_pci_ide_c::timer()
     BX_DEBUG(("WRITE DMA from addr=0x%08x, size=0x%08x", prd.addr, size));
     DEV_MEM_READ_PHYSICAL_DMA(prd.addr, size, BX_PIDE_THIS s.bmdma[channel].buffer_top);
     BX_PIDE_THIS s.bmdma[channel].buffer_top += size;
-    count = BX_PIDE_THIS s.bmdma[channel].buffer_top - BX_PIDE_THIS s.bmdma[channel].buffer_idx;
+    count = (int)(BX_PIDE_THIS s.bmdma[channel].buffer_top - BX_PIDE_THIS s.bmdma[channel].buffer_idx);
     while (count > 511) {
       if (DEV_hd_bmdma_write_sector(channel, BX_PIDE_THIS s.bmdma[channel].buffer_idx)) {
         BX_PIDE_THIS s.bmdma[channel].buffer_idx += 512;
@@ -309,7 +309,7 @@ void bx_pci_ide_c::timer()
     DEV_hd_bmdma_complete(channel);
   } else {
     // To avoid buffer overflow reset buffer pointers and copy data if necessary
-    count = BX_PIDE_THIS s.bmdma[channel].buffer_top - BX_PIDE_THIS s.bmdma[channel].buffer_idx;
+    count = (int)(BX_PIDE_THIS s.bmdma[channel].buffer_top - BX_PIDE_THIS s.bmdma[channel].buffer_idx);
     if (count > 0) {
       memmove(BX_PIDE_THIS s.bmdma[channel].buffer, BX_PIDE_THIS s.bmdma[channel].buffer_idx, count);
     }
diff --git a/bochs/iodev/serial.cc b/bochs/iodev/serial.cc
index 81bf47772..a2eb5f0a9 100644
--- a/bochs/iodev/serial.cc
+++ b/bochs/iodev/serial.cc
@@ -1551,7 +1551,7 @@ void bx_serial_c::rx_timer(void)
           SOCKET socketid = BX_SER_THIS s[port].socket_id;
           if (socketid >= 0) {
             FD_SET(socketid, &fds);
-            if (select(socketid+1, &fds, NULL, NULL, &tval) == 1) {
+            if (select((int)(socketid+1), &fds, NULL, NULL, &tval) == 1) {
               ssize_t bytes = (ssize_t)
               ::recv(socketid, (char*) &chbuf, 1, 0);
               if (bytes > 0) {
diff --git a/bochs/iodev/usb/scsi_device.cc b/bochs/iodev/usb/scsi_device.cc
index 96cb75ca0..1c76ce1eb 100644
--- a/bochs/iodev/usb/scsi_device.cc
+++ b/bochs/iodev/usb/scsi_device.cc
@@ -282,7 +282,7 @@ void scsi_device_t::restore_requests(const char *path)
     do {
       ret = fgets(line, sizeof(line)-1, fp);
       line[sizeof(line) - 1] = '\0';
-      int len = strlen(line);
+      size_t len = strlen(line);
       if ((len > 0) && (line[len-1] < ' '))
         line[len-1] = '\0';
       i = 0;
@@ -628,8 +628,8 @@ Bit32s scsi_device_t::scsi_send_command(Bit32u tag, Bit8u *buf, int lun, bool as
           case 0x83:
             {
               // Device identification page, mandatory
-              int max_len = 255 - 8;
-              int id_len = strlen(DEVICE_NAME);
+              size_t max_len = 255 - 8;
+              size_t id_len = strlen(DEVICE_NAME);
               if (id_len > max_len)
                 id_len = max_len;
 
@@ -643,15 +643,15 @@ Bit32s scsi_device_t::scsi_send_command(Bit32u tag, Bit8u *buf, int lun, bool as
 
               outbuf[r->buf_len++] = 0x83; // this page
               outbuf[r->buf_len++] = 0x00;
-              outbuf[r->buf_len++] = 3 + id_len;
+              outbuf[r->buf_len++] = 3 + (Bit8u)id_len;
 
               outbuf[r->buf_len++] = 0x2; // ASCII
               outbuf[r->buf_len++] = 0;   // not officially assigned
               outbuf[r->buf_len++] = 0;   // reserved
-              outbuf[r->buf_len++] = id_len; // length of data following
+              outbuf[r->buf_len++] = (Bit8u)id_len; // length of data following
 
               memcpy(&outbuf[r->buf_len], DEVICE_NAME, id_len);
-              r->buf_len += id_len;
+              r->buf_len += (int)id_len;
             }
             break;
 
@@ -769,7 +769,7 @@ Bit32s scsi_device_t::scsi_send_command(Bit32u tag, Bit8u *buf, int lun, bool as
           p[21] = (16 * 176) & 0xff;
           p += 22;
         }
-        r->buf_len = p - outbuf;
+        r->buf_len = (int)(p - outbuf);
         outbuf[0] = r->buf_len - 4;
         if (r->buf_len > (int)len)
           r->buf_len = len;
diff --git a/bochs/iodev/usb/usb_common.cc b/bochs/iodev/usb/usb_common.cc
index 9ba6b7be8..3be2042a2 100644
--- a/bochs/iodev/usb/usb_common.cc
+++ b/bochs/iodev/usb/usb_common.cc
@@ -611,7 +611,7 @@ int usb_device_c::set_usb_string(Bit8u *buf, const char *str)
     *q++ = str[i];
     *q++ = 0;
   }
-  return q - buf;
+  return (int)(q - buf);
 }
 
 #endif // BX_SUPPORT_PCI && BX_SUPPORT_PCIUSB