Cannot install yahoo messenger

try to download the standalone version of yahoo messenger

You need the following OS to support Messenger Windows 2000/XP/2003/Vista/XP64/Vista64
If that is not a problem read on.

Your problem may be due to a mal-function of the uninstall software.
Close all programs when uninstalling / downloading and uploading.
If you tried to uninstall from the Control Panel and failed to back it up with a visit to the C drive, you may have old software conflicting with the incoming software trying to share the same folder.
If you have Vista the whole Messenger folder should have been removed during the uninstall.
Check
Start > Computer >> Local drive (C) >> Program Files >> Yahoo >> Messenger. - The Messenger folder should have been deleted and not seen. If the Messenger folder is still visible - delete it.

If you have a pre-Vista OS, the Messenger folder remains, and inside, only one sub-folder should be seen. This is the 'Profile' folder and contains all the message history. All other software should have been deleted.

Manually delete any other folders and files before moving on

Download 'ccleaner' and run it through a couple of times.

http://www.filehippo.com/download_ccleaner/

Re-start your computer and download Yahoo Messenger from here.

http://www.filehippo.com/download_yahoo_messenger/