I have this same problem and have tried solutions mention here and other places and continue to get the same error message "Cannot start microsoft outlook" I couldn't run the resetnavpane because it would just error. Yes I went to the program files (x86)..... I tried several things - none worked UNTIL I found this regedit- A BIG thank you for this information. I wasn't too upset as I just converted, actually went from is better term, XP Pro 32 bit to Windows 7 Ultimate 64 bit, then loaded Office 2010 Professional Plus. Prior to this I didn't use outlook or anything other than word. What I did use was thunderbird which was fine, but decided to try Microsoft office. I had never even executed Outlook and it stilled errored on the first try! All the other programs in the package opened with no problem. This was one of the hardest, not hardest, but close while doing this change in operating systems. Thanks Again Capt Jack