>Hi,
>
>On one computer I keep getting a 'claas not registered' when opening a form containing a treeview (just the normal one from comctl32). Usually it helps to unregister and register the comctl32.ocx, but in this case nothing happens. This seems to have occured overnight on just one PC. Allegedly the machine's configuration has not changed.
>
>Any ideas?
>
>Thanks,
>
>Auke

Even though the machine's configuration "did not change", check the version of comctl32.ocx with the version you used when developing. If it got overwritten with another version, the form will fail because it can't find the exact version that is associated with the OLEControl.