According to M$ ...heres what SPK1 does
What Was Fixed In Windows XP?
Quite a bit it turns out. The full list is at the XP site. Interesting reading for sure. This also allows you to determine if you want to go ahead with it. And as always, TEST, TEST, TEST in a controlled environment! Just look at what I got back just now:
"I installed SP1 today and it literally destroyed my computer! It asked me to activate again. After I did and rebooted, it went into an endless cycle of rebooting. Would not even start in safe mode! Called Microsoft and had me do a repair. Stopped rebooting but I lost my Internet connection and could not reinstall a dial up connection. I also lost the shortcuts to most programs. They also disappeared from the start menu. An absolute disaster. Have reformatted and in the process of reinstalling EVERYTHING!"
And another one:
"Just thought you would be interested in my experience with WinXP SP1. I purposely installed Windows XP on a box with the infamous FCKGW RHQQ2 YXRKT 8TG6W 2B7Q8 product key with the intent of testing SP1's payload. Curious as to whether or not the service pack would be "chatty". I also started a packet sniffer capture before initiating the install. Contrary to the rumors that have abounded for some time, once the SP unpacked itself it simply informed me my product key was invalid and did not allow me to continue installing. I then tested access to Windows Update to see if somehow some bad mojo had been performed on me in the background, but I had no problems downloading and installing all 20 of the latest updates. I was also surprised that my capture did not reveal any network traffic to Microsoft during the installation. Seems like all these rumors turned out to be much ado about nothing. The only negative consequence of using a known pirated product key seems to be that you are denied access to SP1." Adrien Romo.
Here is the list with fixes: