>>Doesn't sound like the same thing from what you've written, but I had the case where a remote system I was using (seemed to) locked me out after so many months(?) of using it.
>>
>>I was told to switch from XP Home to XP Pro. Sounded weird, but I did it, and I haven't had a problem since.
>>
>>I don't know what the issue was.
>>
>>cheers
>
>Hmmm, who advised it? I hope it's not my case... I'm afraid it could be something my son installed. As far as I recall last time I used RDP was Friday, I made some fixes in my code, then let my son play for ~ 1h. while I was preparing for Shabbos... When I tried at Monday night, it didn't work, and it didn't work since then :(

Use System Restore to rollback your system to the date when it last worked.