Upgrades won't install

[Guest]

I accidentally installed Windows XP a second time on my computer and now none
of my upgrades will install. Is there anyone who can help me!

 

[Gary S. Terhune]

What are the error messages, at what part of the process does it fail?

And how do you "accidentally" reinstall Windows?

 

[Ron Badour]

Are both installations functional or is just one working--can you get rid of
the old one?