If you are experiencing problems updating your Adobe Reader 9.0 with error 1602, try this:
(You will need to be logged in as administrator and have your hidden folders visible.)
1. Exit Adobe Reader,
2. Open Windows Explorer and navigate to the “C:\ProgramData\Adobe\Reader\9.2\ARM” folder,
3. Remove all files found in this folder (I recommend moving them to a different folder),
4. Start Adobe Reader and select Check for Updates (in the Help menu).
You should now be able to get the updates.
If this is successful, you can delete the files you moved to the temporary folder. This problem is related to permissions to access these files. Most likely the problem was caused by a bad installation of Adobe.