Installing Adobe Reader XI from Adobe Reader X

For some reason, I cannot install Adobe Reader XI from X. I have downloaded it, both using the

installer and direct. When I run the package, it says that it is successful, but when I check, I find that I

am still running Adobe X (10.6.1).

I am running Windows XP SP3 HE with all updates current.

My system is 1.6Ghz

I have 2G memory

I have 500GB hard drive.

I have uninstalled X first, but nothing seems to allow me to successfully install XI.

I have reinstalled X.

Please note that I have and use Chrome, Firefox AND IE8.