Originally Posted by toddz
In a nutshell, these two files need to be deleted form the Java directory before you install, or need to be deleted using javaloader after it is installed (although that may be harder).
AFTER you have downloaded and installed the beta OS file to your PC...
1. On your PC, go to C:\ProgramFiles\CommonFiles\ResearchInMotion\Share d\LoaderFiles\**your OS version**\Java.
Find and delete these two cod files.
2. Go to c:\program files\common files\research in motion\apploader and delete the file named "vendor.xml." Vista/Win7 users: In the apploader folder, simply click on "Compatibility files" to see the actual Vendor.xml file. Once you've got that - simply delete the vendor.xml file there (even if you've deleted or think you've deleted it in the folder previously) and voila, it will allow you to update to the newly installed OS!
3. Plug in BB and double click on "Loader.exe." It's located in the same place as the above vendor.xml file.