Vista - Remote Desktop help!!

I recently set up my remote desktop on my Vista Ultimate. Everything was working good, I could access it from the other Vista computer on my network and the Xp one. I also set up a dyndns account to access it outside of my local network. I configured both my firewall and my router for remote access also. The problem I'm having is now just out of the blue I can't access the computer from anywhere. Not the Vista or the Xp computer and certainly not outside of the network. I've gone through all my settings and everything is set up the same. I get an error off of the Xp mechine that says "An authentication error has occured (Code: 0x80090330). I'm trying to access with the ip address becasue using the computer name never worked for me.

The error means that "the specified data could not be decrypted"

so how do I fix this so i can use remote desktop?

On the client side, how did you configure? Did you choose: Always connect, even if authentication fails ?

thats how its been setup

OK, so try to enable the "enablecredsspsupport:i:0" option in the default.rdp, it should solve your problem (i hope)

Where do i access that? And I'm guessing i do it on my vista computer running the remote desktop?

You have to add this option in the rdp file

where do i access the rdp file?

If you did not move it, it should be in your "Documents" folder.

You can edit it with notepad