|Log onto your account the way Thomasad has explained. Once logged on, Click Start and Run. Type in "regedit" without quotations and hit enter. Navigate to:|
In the right pane, look to see if your user account name is listed. If it is, right click it and hit modify. Enter "1" into the box (without quoates) and hit Ok. Restart your computer and see if you user account is now listed.
If it is not listed, right click in the white area on the right pane. Select New -> DWORD Value. Give it the exact same name as your username account. Modify it as explained above and enter 1 as the value. Hit Ok and restart your computer.
Let us know if this has worked for you.