About two months ago I built a small server to host my web page. The specs are as follows:

Pentium II 300mhz
128mb ram
Fedora Core II
9gb HD

For several months the server ran just fine. About a month ago I added another 128mb of RAM (RAM that I tested as good).

About three weeks ago I began experianceing hard freezes for no apparent reason. What I mean is, the computer is working just fine one day. Then, a few hours latter, I'll try to bring up the web page, and nothing happens. Or I might be in the middle of an FTP transfer, and the computer freezez tight. So Tight that nothing(caps lock, num lock, or even the mouse) works. I am forced to do a hard reset. It usually works for a day or so then, and then locks. Since I buitl it, several minor kernel updates have been downloaded. I have tried all of them, both the newest and the origional, but nothing fixes the stability.
I know that the problem is lickly ram or the hard drisk. Is there any log files I check for clues (an what I should specifically look for)? Are there any soft of scandisk like utilites or other file system checkers I can run to find some sort of problem?
Any ideas would be great b/c I don't really want to have to rebuild the entire server from scratch again.

thank you for your help.

by hardware ~ implies a faulty component. To eleimnate hardware, reseat RAM, Processor & IDE\SCSI connectors ~ ideally replace the RAM ~ even more ideally replace the motherboard ~ the latter is the most likely source of you fault