How do I use reg.exe to complete this task? ?

I have an issue in windows xp. When I login to my user account the account logs off immediately placing me back on the login screen. I also have the same issue in safemode. I have found this is due to a key in the registry that has been altered by malware.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\…

Edit the Value “Userinit”

To %26quot;C:\WINDOWS\Explorer.exe,%26quot; and not %26quot;C:\WINDOWS\system32\Explorer.exe,%26quot;. include the comma.

Click Start, Run and type REGEDIT. Navigate to:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\…

In the right-pane, change the value of Userinit to %26quot;C:\WINDOWS\system32\userinit.exe,%26quot;

Type the above value exactly as given, including the comma - exclude the quotes. Also, change the path to userinit.exe appropriately if Windows is installed in a different drive.

Close Registry Editor and restart Windows.

How do i do this without logging in?How do I use reg.exe to complete this task? ?
I presume this means you haven't been able to log in using the system administrator account as well?



http://support.microsoft.com/kb/321305 - the article on how to log in as an administrator



Is this account password protected?



if not, the best way i can see of doing this is setting that drive up as a slave drive, in another computer, so you can go through it and access that file......