Help repairing XP installation

[j_in_vegas]

I have XP Professional that refuses to boot up (not even into safe mode)... just gives me a black screen with a non-moving cursor in the middle of the screen.
I do not have the original installation disk, but was under the impression after searching the www that I could use any XP cd to repair the install. Halfway through the repair, it's asking me for the product key. If I enter the key from the cd I'm using, is that going to mess up the install  on my oher computer?
Anyone have any thoughts, suggestions, workarounds?

[therepairman]

It should be fine. If your installing it on your laptop try to look for a Product Key sticker underneath it. As Windows XP has many different versions, getting the right version to match your product key is not an easy task. On the otherhand if you can bypass the product key option, once the installation is done. Download a tool called Key Update by Microsoft and that should allow you to reactivate your orginal windows key.

[vietlockerz]

let put in cd winxp install then restart your computer with cd boot of winxp install .After that you put "R" to repair your windown

[keveenjones]

If  you can use previous key that is same in previous cd, so there is no  any issue regardig now you can use another cd. You can use another cd  with out any problem microsoft published some product key so you can  use that cd product key easily.