これで治るんじゃね?
http://support.microsoft.com/kb/927824/ja


Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\i8042prt\Parameters]
"LayerDriver JPN"="KBD106.DLL"
"OverrideKeyboardIdentifier"="PCAT_106KEY"
"OverrideKeyboardSubtype"=dword:00000002
"OverrideKeyboardType"=dword:00000007