Back in December I told you about Windows 7's little-known application-compatibility troubleshooter, which I'd used to try to resolve a problem with iTunes.
As it turned out, the reason iTunes wouldn't sync reliably with my iPhone had nothing to do with compatibility. (The culprit was an obscure Windows 7 glitch involving USB devices--one that I solved using this Microsoft hotfix!)
Unfortunately, even though I'd turned off compatibility mode for iTunes (by right-clicking the iTunes icon, choosing Properties, clicking the Compatibility tab, and clearing the Compatibility mode checkbox), the program generated this irksome message every time I ran it:
iTunes.exe has been set to run in compatibility mode for an older version of Windows. For best result, turn off compatibility mode of iTunes before you open it.
Sigh. Stupid Windows. Or maybe stupid iTunes. Either way, compatibility mode was "off," but iTunes didn't think so.
Fortunately, I finally found a solution:
1. Make sure iTunes isn't running.
2. Click Start, type regedit, then press Enter.
3. Navigate to this Registry location: HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
4. Look in the main pane for a key that refers to iTunes. If you find one, delete it, then exit the Registry.
5. Start iTunes. The offending message should be gone!