How do I remove corporate administrator settings? I have an HTC Desire C, just a couple of weeks old. I also have a new job and decided to add my work email account via Exchange activeSync, however once it became apparent that I was giving up rights and functionality (such as the screen pattern lock) for my own phone I decided to remove it.

I removed the administrator, which automatically removed the email account, however I am still unable to restore the screen pattern lock. I've restarted the handset a couple of times, no help.

I seem to have no options to view or delete and administrator accounts (presumably, and hopefully, because there are none now).

I've read the similar question posted here and the answers but they don't help me sadly. Any ideas?
Converting my comment into an answer, as it proofed according to its follow-ups:

In a thread at XDA, a user states:


  I had the same problem when i tried to setup an exchange email account and installed a certificate. Fixed it by deleting all certificates. Settings>Security>Clear credintials


So I'd suggest you just do that.

For additional information, also take a look at this thread at Android-Forums, which deals with the same problem you mention as example in your question ("screen pattern lock" -- here: disable lock screen).