been getting this error on my windows xp machine
Post a detailed error message please
What is your client OS?
From what you said, this is a Windows XP client
What is your server OS?
What is your UrBackup Server version?
Judging by the picture you are using a 2.X build
What is your UrBackup Client version?
When did this occur, or has it started occuring since you added the client?
Have you taken a look at your logs inside of your UrBackupServer folder?
Is this your only client giving you problems?
Have you tried uninstalling and reinstalling the client on this machine?
What steps have you taken so far to attempt to resolve this?
Have you ran any of the batch scripts inside of your UrBackupServer folder (Namely remove_unknown, database_cleanup, cleanup, or repair_database?