ITunes error message on installation

Question

whenever I try and install iTunes, an error message comes up:
there is a problem with this windows installer package. a program required required for this install to complete could not be run. please contact your support personnel or package vendor.
can anyone help with this?
thanks.

Answer 1

The response to "Echo %appadata%" should be
C:\Users\UserName\AppData\Roaming
A space in the user name shouldn't be a problem, but creating a new user may fix the problem because it will create the account with default registry settings which will hopefully have the missing %appdata% information.
If you want to check on this before creating the new user, just for curiosity's sake, check the following Registry key:
HKCU\Software\Microsoft\Windows\CurrentVersion\Exp lorer\Shell Folders and check the value for AppData in the right hand pane. If it's missing, then that would explain the problem. It should be as listed above, substituting the UserName with the folder name for the user under Users.
Also check the key
HKCU\Software\Microsoft\Windows\CurrentVersion\Exp lorer\User Shell Folders
The value of this key should be
%USERPROFILE%\AppData\Roaming
More keys to check:
HKCU\Volatile Environement (1)
HKU\.DEFAULT\Software\Microsoft\Windows\CurrentVer sion\Explorer\User Shell Folders (2)
HKU\Sxxxxx\Software\Microsoft\Windows\CurrentVersi on\Explorer\User Shell Folders (2)
HKU\Sxxxxx\Volatile Environement (1)
The values in (1) should have the full path spelled out, the values in (2) should use the %USERPROFILE% variable in the path. If the value under HKU\.DEFAULT is missing or bad, then creating a new user probably won't work either. If that value is missing, then I would recommend a clean reinstall of Windows because there is no telling what else is messed up also.