I have never used registry cleaners but it seems like I will try one in the near future. Well, that's a half-truth. Years ago, I have scanned and checked but never actually cleaned. In relation to the problem discussed in Adobe Acrobat 9 not connecting to activation server, after uninstalling Acrobat 9 and having cleaned using Adobes tool, I think that I will do a registry scan using CCleaner. I'm aware of the pros an cons using registry cleaners and have been safely lodged on the "cons side" but would it be possible to pinpoint registry entries from a specific program? In addition to Acrobat, my friend also has Photoshop from Adobe installed which might make it more complicated.