In case anyone is having problems on their Windows XP machine with this recent update (as of the post date) there is a fix for it. I'd suggest following the link here, but for those who so happen to be too lazy and not click it I'll post the fix instructions here:
1) Open Command Prompt
2) Type the following and press enter: ren %windir%\System32\msxml4.dll msxml4.old
NOTE: You may get an error saying "Cannot find the file specified", just ignore it and proceed.
3) Type EXIT and press enter (or just hit the X button, whichever you want to do)
4) Visit the Microsoft Windows Update site and install the fix there.
I know it involves fiddling with something in your System32 folder, but it is 100% safe. At least you won't get prompted to install it repeatedly.