Hi Guys,
I just wanted to throw this one out because I had an issue come across my path three separate times in the last couple of months on different XP machines I work with. It's an issue where the machine experiences massive sluggishness. If you're running XP and have any local lag issues this might be it.
When checking the processes under Task Manager one of the svchost.exe processes was found to be going flat out at 99-100%.
I've done some digging and found information with many others having experienced this in the last few months. It appears the svchost process in question is tied to Windows Update and the problem with it is a result of Windows Update being heavily linked to Internet Explorer. Basically, if IE is out of date it can adversely affect the performance of Windows Update.
Obviously, an immediate relief fix is disabling Windows Updates. However, if disabling updates isn't an option then the more permanent fix is to update IE. I've found that getting IE up to at least version 8 has sorted it for me so far.
Hope this helps anyone else who's battled this one.
Shout out to this Neowin thread which pointed the way forward (this post in particular).