My fathers computer keeps on freezing on him. It happens at different times, he will be doing something and it will freeze, sometimes it will freeze at startup. He has windows 98.
I'm no computer guru but first I'd try a scandisk to clean up the hard drive. Adding RAM may help too. If the computer is running Win98, I'd guess that it's a few years old and many websites and software today are pretty graphic intensive. If the machine just can't handle them it may freeze up.
first, make sure you have good anti-virus software and it is running. then, make you sure you have the latest DAT files (the most up-to-date virus data for you AV software) installed.
do a complete scan for a virus
then download, update and install ad-aware (or spybot)