Windows XP SP2 hangs at login

[Guest]

I recently tried to install an application on a PC running Windows XP SP2.
The install failed with an error saying that a certain .dll file failed to
self-register. The file was "cpeault32.dll", I believe. Ever since then, I've
been unable to login to this machine with any user account, including the
local administrator account. When I type a username and password, it goes
through the motions of loading my settings, then hangs completely. I'm able
to CTRL+ALT+DELETE to the Task Manager and get a command prompt, but that's
it. Thoughts?

 

[John John]

Can you start in Safe Mode or using the Last Known Good?

John

 

[Guest]

Apologies. No, I cannot start in either mode. It's as if the OS has just
disappeared on me.

 

[John John]

Did you try safe mode with command prompt? When you do the
Ctrl+Alt+Delete you say you get to a command prompt, can you run
anything from it? Possibly you could do a System Restore from there?

%systemroot%\system32\restore\rstrui.exe

John

 

[Guest]

Tried that just now. When I run rstrui, I get a black window labeled "System
Restore", and nothing happens. Am I looking at a reinstall?

 

[John John]

You could try launching the Recovery Console and try to disable the
offending service, or to enable a service that was disabled by mistake:

Description of the Windows XP Recovery Console
http://support.microsoft.com/default.aspx?scid=kb;EN-US;314058

Use the listsvc command to see the services and their startup setting.
Use the disable command to disable unwanted services. Use the
enable command to enable a service. For help while in the Recovery
Console type help and press <Enter>. For help on any command use the
/? switch, example listsvc /?

How to Disable a Service or Device that Prevents Windows from Starting
http://support.microsoft.com/kb/310602/

By the way, I did a search on cpeault32.dll and I find nothing. Maybe
you made a typo in your first post. When you are in the Recovery
Console you will get a list of services with the listsvc command.
Search the net to see which might need disabling and which are essential
for the proper operation of Windows and that may need to be enabled if
they were turn off by mistake. It might help if you tell us the name of
the application that you were trying to install, others here may have
had experience with it. Also, maybe there is help or information on the
website or the software vendor

John