I know this issue has been addressed before. When I set up a new user or power user account, some programs "reinstall" but get hung up with a internal error 2503 and the programs, particularly MS Office 2007, will not load. I have changed permissions of system, administrators, users and power users in windows\installer, mso cache and a host of other potential problem areas, all to no avail. In other posts, it mentions a registry fix in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer . It said to "change" the key to; Administraotrs - Full System - Full Everyone - Read On my system, there are no such registry keys. can someone please tell me exactly what type of keys to create and what to write in them. In simple, id*** proof detail. It was mentioned to "propagate" the key with inherited permissions. i have no idea how to do this. thanks. Also, if there is another/better fix to this issue, please advise. Thank you.