Service Pack 3 install?

Is there any reason Not to install service pack 3 for Windows XP? I have IE8 but I use SeaMonkey or Firefox3 almost exclusively. My SP2 seems to be missing some files (old scratchy disc), so I think I can fix that by installing SP3.

 

There's a lot of mixed results with XP's SP3. For some folks, it installed great and runs great. For others, the exact opposite; the install was a nightmare, and now their PC's are running all whacky. And for others, it installed OK, but the PC just isn't right. I think that if your PC is running 100% healthy, SP3 will install and run OK.... and I mean 100%, not 99.8%. I think that a very slight, practically invisible little problem could balloon up into a massive mess with the SP3 install. But that's just my opinion. Here's a link to a thread about SP3 I started a while back that's full of peoples experiences (both good and bad) with SP3, about 4 pages worth. You might find it enlightening, or at least interesting. http://forums.majorgeeks.com/showthread.php?t=158040

 

I installed SP3 from the Major Geek download site and no issues.