M$ admits that XP SP1 may cause certain programs to creep along on your PC. The article can be found here.

Microsoft Windows XP SP1 May Make Applications Crawl

By Techweb News

Microsoft acknowledged that Windows XP Service Pack 1, a broad update released last October, can cause applications on some PCs to slow to a crawl.

The problem stems from changes in Windows XP SP1's memory management system, and occurs when frequently run programs allocate and de-allocate large blocks of memory. Such programs can take up to 10 times longer to launch, Microsoft said.

Although a fix is available, it's not posted on the general Windows Update site. Instead, users who experience this problem must contact Microsoft Product Support Services by phone to acquire the patch.
I'm not sure but this sounds like it might have been intentional...perhaps a ploy to seek out unregistered/unactivated copies of MS Windows XP... Any thoughts????

The Eeshman