Bryan, your problem has nothing to to with Windows. If it boots and runs
without crashing, it's fine. You don't need to reinstall it.
Since you say the system is several years old, perhaps you need to 'clean
out the clutter'.
Start by running Disk Cleanup. Then right click the desktop IE icon, click
Properties. Clear out your History and Cookie files. When the Cookies are
deleted you will need to reenter ID's and passwords for any online sites you
visit, so make sure you have those available before you delete Cookies. Next
run Disk Defragmenter.
Then I would open the case, and blow it out with air, making sure to clean
the case cooling fans, and the CPU heatsink/fan. Intel CPU's slow down if
they overheat. Check all fans for proper operation, and make sure case air
intakes are clean.
Finally, I'd do an online system scan to check for viruses and worms. You
will need to 'unhide' system files to get a full sweep. To do that, Control
Panel-Folder Options-View-Show Hidden Folders-Uncheck Hide system operating
files. Click Apply-OK.
Two good sites are, Online Housecall from
www.trendmicro.com. and
www.ewido.net.
Once the system is clean, create a new restore point using System Restore,
and rehide your system files.