download the uninstaller and installer directly from the links from this page: http://forums.adobe.com/message/3952360
if you have a 64-bit system, you will only need to download the 64-bit installer. it will install 32-bit ninaries also...
You need to run the installer as an Administrator user.
If you already did that, then you will need to fix the permissions of some registry keys; follow the instructions in http://kb2.adobe.com/cps/494/cpsid_49419.html