Error 774 Windows Media Center fails to record
This is a Windows Media Centre error related to failed recordings (eg recording TV shows, etc..)
First thing to do is delete the backup recordings, these can be located usually in one of the following folders
(depends if you changed anything from default install)
Then like most windows problems, stop and restart the Windows Media Cnetre Services.
Windows Media Center Extender Service
Windows Media Center Receiver Service
Windows Media Center Scheduler Service
Windows Media Center Service Launcher
Windows Media Player Network Sharing Service.
Here is a link from Microsoft on this as well:
Why didn't my
TV show record in Windows Media Center?