A system restore does not always fix a problem. Its a last resort measure.
Msconfig is a tool for disabling software that can cause problems on a PC. Just make sure you DO NOT disable Microsoft wireless mouse or keyboard. If Msconfig does help in finding the problem, the next step is to find the offending software and that can be a painfull process.
Try this first:
1. Right click on C:\ and select properties
2. Go to the tools tab and select Error Checking and click on Check Now
3. Place a check mark IN BOTH boxes and select start.
4. Restart your PC
5. When the PC start, let it do its thing and wait (This will take some time. )
If this does not help do a XP Defrag. (This may also take some time)
Other things that might help:
1. Registry Cleaners (CleanMyPC) software
2. Virus software
3. MalwareBytes software
4. Clearing your cookies and *.tmp files
Last resort is to reinstall XP
Some of this is very time consuming (2-4 hrs) but needs to be done as it will identify potential HARD DRIVE problems, Xlinked files and Virus/Spyware.