Having Windows Problems

I am running Windows XP SP3, IE 7, on 2.2 mhz Dell system with 1 gb memory. I am running Webroot antivirus, Windows Firewall and Anti-spyware and I am having trouble with several Windows components.
I have problem browsing from IE some pages trying to sign-in , on some webpages I can sign in but comes to either a blank page or page with just titles. I do have Firefox installed and it works just fine.
can't acccess " Help and Support " or run "system restore"
I have already tried several things, I have installed CCleaner and clean up the system, have run scans on anti-malware, anti-virus, and anti-spy software and the system is clean.
What can I do? Thank you very much.

You appear to be vigilant against malware. Outstanding!

For what you describe, I recommend starting with RIES - reset IE settings
link courtesy of kimsland

The concluding line of the link - follow the 8-step malware removal guide.

Consider that option.