Reinstall XP home if necessary

[systempat]

I may want to do a reinstall of XP Home on my system. The main reason is that the boot-up time for Windows has become too slow. It's now 4-5 minutes on an Athlon X2 5200+ where it used to be about 1.5 minutes. It runs fine once it's up. It's the slow boot time that annoys me. I've tried disabling services as much as possible but it has not helped much.

If I DO reload it, how to keep the reinstall pain to a minimum. I'd like to keep software installed if possible, so that means a repair install. I have the XP home CD that goes with this PC, and it's a late enough version that SP2 is included. But it will have to go back thru all the patches since SP2 was released. Are these still saved on the system somewhere so I don't have to get them downloaded again??
One of the situations that I'd like to avoid is going to the Internet until the security updates are in place. If I already have the patches from the last time, it save 2 things. saving the hour that it takes to download them, and being connected to the Internet for that hour with out-of-date security.
So my question is - are the patches that Microsoft Update has used saved on a Windows folder? And do I need to save these to a CD so they can be re-applied?
------>>> Pat