reinstall or repair XP

Besides a clean setup (I recommend a low format first), I
must add that not any anti-spy is good.
First of all, many of them are spies themselves, and they
do much harm.
I recommend LavaSoft ad-aware. Clean, free, and this guys
deserve my gratitude.
I really do.

-----Original Message-----
I downloaded a program called spysweeper which identifies
cookies and then lets me delete them. I must have deleted
something that I shouldnt have, now I have all kinds of
problems.
I tried to reinstall XP, the disk only shows me
documentation etc, when I click on it it tells me to
reinsert the disk, which I did, but I keep getting the
same message,
when I try to reinstall from the run prompt, it tells me
that I cant install from windows 2000 (which I did
originally, but go to windows 95 or 98 to install.
can anyone help me?
Thx,
Wolf
.