Can't log-on to Windows XP?

My computer was infected with a virus: Internet Security 2010. I tried removing it manually by deleting the following:

I%Program Files%\InternetSecurity2010\IS2010.exe

%System%\critical_warning.html

%system%\winupdate.exe

%system%\winhelper.dll

HKEY_CURRENT_USER\Software\Internet Security 2010

HKEY_LOCAL_MACHINE\SOFTWARE\Internet Security 2010

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run “Internet Security 2010″

C:\WINDOWS\system32\winhelper86.dll

C:\WINDOWS\system32\winlogon86.exe

C:\WINDOWS\system32\winupdate86.exe

I followed the instructions from these two sites:

http://www.spywarefixpro.com/remove-internet-secur...

http://news.loaris.com/internet-security-2010-remo...

I think I was able to remove most of the pieces of the virus but when I went to reboot my PC, it logged me on for a second and then immediately logged back off before anything on the screen could show up. I'm thinking I may have deleted something accidentally in the process of clearing my PC of the virus. I don't have the WINDOWS XP disk, or otherwise I would reload WINDOWS XP entirely. I've been trying to fix it through Windows Recovery Console but to no avail. Anyone know what might be the problem and how to fix it?