How Can I Fix this in Windows 7

I didn't know what might have caused this error. An annoying message pops up from time to time and then hangs my machine afterwards, so I have to restart it. A lot of important documents got corrupted because it interferes every time I'm creating a new document or spreadsheet file. This is the error code:
Error_ipsec_default_qm_policy_not_found
How can I get rid of this error? What could be causing this in my system?
