3 XP computers are slowing down

[Guest]

I have three XP Pro SP2 computers running 24/7. About a week ago, all three
started slowing down when starting up orograms like email clients, IM panels,
and even Windows Explorer.

All the usual solutions such as defrag, reboot, cutting out useless
background programs, checking for spyware/malware, running virus scans, etc
haven't helped a bit. If i look at Program Manager when starting an
application, the executing program gets almost all of the CPU time (over
90%), but doesn't appear to be doing anything on the screen. I might get the
startup panel outline, but then it appears to hang for several seconds
(sometimes up to 10/15 seconds) before finally opening up and running.

Has anyone else noticed this? There have been quite a few updates from
Microsoft during that last week and I'm wondering if any of those might have
caused this.

All 3 computers have at least 1Gb of RAM, and the CPU runs at least 1.5 Ghz.
Hard disk space is at least 22% free on the OS partition.

GP

 

[Guest]

Further information: Upon examining the Event Log I find that Windows
Defender has an amazing amount of entries in it -- all Info entries, but
entries nonetheless. This tells me that Windows Defender is running in the
background far too much. I stopped it on one of my computers and regained
quite a bit of speed of response in it. Could this program be causing so
much slowdown in the system?

There are no other Warning or Critical events in the log, just the Info
ones from WD.

GP