Periodically over the past few weeks to a month, my system has been locking up completely, at random times, and I am not sure whether it is a software conflict, an internal system problem, a virus, bad hardware, or something else. At times it locks up even before startup, sometimes after a few hours, sometimes a few minutes. First, my tower will make the normal-sounding [this is going to sound stupid but i don't know how else to put it] computer "thinking" noise, such as that you hear when Windows first boots up. This noise then stops abruptly with a barely perceptible "click" and then silence. Then the icons stop working [meaning, they don't do anything when clicked on - they don't even highlight], and a few seconds later the keyboard and mouse stop functioning and "lock up" as well. All this happens in the span of approximately thirty seconds. The computer does not shut off, it simply stops working, and because I have no access to the Start menu after the lockup, I must then manually turn off the computer without going through shutdown. I'm sure this isn't helping the problem, but it is really the only thing I can do, as far as I know. Ctrl+Alt+Del does not work either.
Usually, this problem occurs when I am executing one or more of the following: Internet Explorer, Microsoft Word, ITunes, PCTV Vision [a television card for the PC], or MSN Explorer with Verizon. [Not all at the same time, but occasionally one or two are running simultaneously.]
I have a Compaq Presario system with an additional slave hard drive and a recently replaced power supply/fan. I'm running Windows XP, and McAfee Personal Firewall and Antivirus. I am, however, concerned because I am currently at college and I know that new viruses often spread easily through college networks. I don't know if a virus would do this to my computer, but perhaps someone has heard of my computer's symptoms and knows what might be causing it... Also, last week my father and I erased the hard drive and started over from our original system boot disks. It unfortunately did not fix the problem. I have also tried to disable any extraneous unfamiliar processes using the Task Manager [i do know which ones NOT to close.

]. This did not affect the problem either. I am shocked that I was able to use my computer for the amount of time needed to write this message.
Any help would be GREATLY appreciated.. final papers are approaching!
Please let me know if you need any additional information. Thank you SO much.
Edited by raqr, 30 March 2006 - 05:52 PM.