Upgrading to Adobe 6.0
If you are having trouble with Adobe Acrobat Reader 5.X or earlier, the best bet is to upgrade to Adobe Reader 6.0.
The first step is to remove all older versions of Adobe Acrobat reader
For Adobe Acrobat Reader 5.0 & 5.1 use the Windows Ad/Remove programs feature.

For Acrobat reader Version 4.0 use the uninstall program.

For Acrobat version 3.0 simply delete the
folder at C:\program files\adobe\acrobat 3.0
Once the removal is complete, go to Download Acrobat Reader and follow the directions to install Acrobat 6.0.