upddlg error

I get a message that says that there was an illegal operation and an “upddlg error” has occured.It generally happens within the first 10 min of connecting to the internet and prior to that the system runs very slow.After the error occurs and once I click on OK on that error,it returs to normal……I would be glad if anyone of you can suggest some steps to be performed to get rid of this and provide some information as to what it is all about.