System Restore not working isn't your only problem.
You still haven't given any details of your system, so it is, still, difficult to give appropriate advice, but you may find the list below useful. Your system details are important, eg processor speed, and how much RAM you have may affect a computer's performance. What size hard disk and how much free space is on there could also be significant.
1] SpySubtract has now been taken over by Trend Micro and is called Trend Micro Anti-spyware. Norton 360 is an all in one security application, including anti-virus and anti-spyware. I don't know what your AT&T Online protection includes.
The thing is, too many applications running in the background checking the same things can slow a system down. For example, if your SpySubtract, and your Norton's 360, and your AT&T Online security, are all checking for spyware in the background, then they will be conflicting with each other. The rule is as follows;
a) Only one Firewall
b) Only one anti-virus running in the background. Keep it's virus definitions up to date.
c) Only one anti-spyware running in the background. Keep the spyware definitions up to date. It s a good idea to have more than one anti-spyware utility, because no one utility finds all the spyware, but use the others only intermittently, to double check the main one.
2] Have a look at some of the "Tips and Tricks" in the forum below;
In particular, look at Grif's post about "How to shut down unnecessary startup programs".
It may be that you ave too many programs that try to startup when you turn the computer on. Many programs try to get you to allow this when you are installing them because they want your undivided attention focused on their programs. But it is completely unnecessary, and when you see any options to "Load on startup" or similar, de-select it.
Also in Grif's tips, look for "How To Clean Unwanted Files From The Hard Drive".
3] I would ask a second opinion on whether you have any viruses. I would goto Housecall at http://housecall.trendmicro.com and have the site perform a full scan on your system, and delete everything it finds.
I hope that helps.