Mac OS

Sometimes it's more time efficient to just uninstall and download the latest version. Uninstall from Control Panel via Add/Remove programs. Then navigate to c:\ProgramFiles and delete any Adobe file left over. Then download the latest version of Acrobat Reader and all should be fine.

When you attempted to re-install the program did you download a new verison of the install?

Or did you simply reuse the one you had already downloaded?

Perhaps the downloaded install was damaged.

Also does it work if you download an older version of Adobe?

Try **** some basic maintenance to your computer. Run a scandisk (chkdsk /f and /r) on the hard drive, run a defrag.
Check for adware/spyware with Ad-Aware, Spybot, Microsoft AntiSpyware, CA PestPatrol.
Check for viruses (I recommend CA AntiVirus).
Uninstall adobe, remove any leftover files (like stated above) and then download adobe again and try a reinstall after you have done your maintenance... Good Luck and Post Back!

Recent installers of Adobe products have become increasingly
fussy about which products have been previously installed. As
part of their anti-piracy strategy, the uninstallers do not remove
some of the hidden files, sometimes resulting in subsequent
incomplete installations or the installer failing to launch at all. It
might help to do a search for all files, visible and invisible that
contain 'adobe' in the name to get a complete list of files to
remove and then try installing again.

HTH,

paul

You don't say what Mac OS version you are using but did you run Repair Disk Permissions from the Disk Utility in the Utilities folder? Did you log on as an administrator when you installed it? Also, you might try deleting the Acrobat preferences. It will automatically remake them when you launch Acrobat.