Laptop is Toshiba Satellite A300-1MM ( Pentium T3200, GMA 4500M, 250GB...) with preinstalled x32 Vista Home Premium.
Initial problem seemed to be just forgotten password. I tried to enter safe mode, but it stops for few seconds after loading
crcdisk.sys driver and continues booting in normal mode. I've tried renaming pcmcia drivers, but no luck.
Next, I tried to add administrator to startup screen. I've used another Vista's installation DVD to open recovery console and
command prompt and use "net user Administrator /Active:yes". It showed no errors.
I don't know if it's important, but "net user" listed only Administrator and Guest accounts, not usual account which is displayed at start screen.
This account is displayed as "USERNAME." ( with . ), but user folder on system disk is "D:\users\username"
Next I tried with manual registry edit in recovery console. In HKEY_LocalMachine\Software\Microsoft\WindowsNT\CurrentVersio\Winlogon\. I've added key SpecialAccounts and sub-key UserList , and Dword Administrator with value of 1.
I noticed that after rebooting, registry forgot all changes I've made.
I also noticed that Shell variable which should be explorer.exe is "cmd.exe /k start cmd.exe".
I googled that and it turned out to be virus Win32:Sality.
I've scanned entire laptop with Kapersky disk but it reported no virus.
Toshiba has option to restore system partition to factory settings but
I can't do it because it asks for password which I don't have.
I've tried retrieving password with OPH Crack, but it reports "not found".
You can try running a chkdsk /r in the repair console. Or, use the vista disc to repair your windows install. If crcdisk.sys file or the sector is damaged, one or the other should fix it. Then you should be able to get into safe mode.