unstable system

Don't know if this is hardware or software related, I'll post in both.
Dell,E520 Dimension, Intel,dual core,2 gig ram, running Win XP Media SP2.
I spend almost all my time in Office suite 2007 or browsing the web with Netscape.

In the past several weeks,my system has started to freeze up, haven't noticed a pattern except that there's usually several things open and the machine has been on for a half hr or so, but since thats always the way I use the machine,not sure if thats a pattern
When it freezes, it starts in stages,things slow down,windows / tabs & programs take a while to open or close, then at some point it'll freeze completely and the only way out is a hard shutdown.
It always powers right back up but will eventually do the same thing.

Looking for ideas where to look.
New ram, took everything out of the case,cleaned connections and reinstalled, all updates installed except SP3.CPU fan clean and working,no way to monitor temps.
Have heard it could be a power supply issue
Any Idea's
Bob
rzoppa@hotmail.com.

 

Trend micro internet security 2008 with the latest updates, had gone to 2009 in Jan 09 but was told by Trend Micro that it would cause problems with Win XP media edition, so went back to the 2008 version, Disabling it does not help.Use windows firewall.
Will load the apps you mentioned and post the results, Have checked task mgr and nothing seems to be hogging resources the commit charge is usually less than 25% of total.

Could registry problems cause this?
Have also had the BSOD twice with the comment Bad_pool_header at the top.

 

use ccleaner to fix your registry, and make sure all of your drivers are up to date. more specifically, your network card. It seems this may be the culprit.
http://majorgeeks.com/CCleaner_Slim_d4191.html
click on the registry tab, and scan for issues.

 

new issue, I ran XP's repair feature and it keeps hanging up at several points,currently at the 32 min mark -
Anyone know how to get out of the repair loop? At this point I can't even get where I'd need to be for a full reinstall, when I reboot it returns to the same place -resume restore- can get to bios and setup, have disabled everything I don't need but it still hangs.

is there a thread for xp repair issues?