Remove XP update, but which?

[muno]

I accidentally (yeah right) installed an update to XP, which caused the system to think it was improperly shutdown and run chkdsk on every startup.

I would like to remove the update, but I don't know which it is. The updates are with Q-numbers on the add remove programs, with no explanation of what it did repair.
I will not write down all the Q-numbers and check them against MS KB - the computer is at home, with no internet connection.

How will I be able to tell which update I need to remove to return the computer to functional state?

If you know the Q-number of that particular issue by memory, please tell me. If you know a tool that will tell what each update does (at home), please point me to the right direction.
-M

[muno]

I can't believe this needs a bumb.
-M

[muno]

And now I feel pathetic.
-M

[rekless]

system restore?


rek

[muno]

That's disabled, and it's been too long for a restore anyway.

I can't believe there isn't a way to tell which update does what, without checking them individually against ms kb.
-M