Clinton -

A major problem with reinstalling the OS (with WinXP), is that unless you got it new within the last couple of months you will need to install the Service Releases that came after publication of the OS.

Unless you ordered the SR1 CD when it was new, the SR1 update can be an 800 MB download. I don't know what size the SR2 update is.

Until the Service Releases are installed, you are vulnerable to many well known and frequently exploited vulnerabilities.

If you think you're lucky, you can install the OS and just go to the Microsoft Download site and start getting updates - but unless you have a very fast connection, you can depend on at least a week before all the patches are in place.

Being lucky isn't impossible, as most "modern" AV programs/firewalls are equipped to block known threats, but it's still a large task to reinstall and get up to date.

With Windows (any version) an OS reinstall often will mean reinstalling a number of other programs, since they have to be run through the installation hoops to be entered into the new Registry files in order to operate properly.

A minor problem with reinstalling the OS (with WinXP) is that it's almost never necessary, if you use the tools that are there, and with at least a few of the more recent scamware/spyware ploys it WON'T FIX ANYTHING, although it can conceal a couple of them and make them incredibly difficult to remove properly.

Reformat and reinstall is being used more frequently by some large IT departments, since there are a very few threats for which that is the only reasonable fix; but they have the advantage of having a fixed software setup that can be mirrored to a reformatted drive,and often all the "authorized" user files are kept on servers. Few human users (not IT administrators) can even remember all of the other stuff that needs doing to completely replace all the crap that accumulates if you're actually using your machine.

John