Below is a list of keyboard shortcuts for use withing MCE 2005.
You won't need most of these if you have the remote keyboard but they are good to keep handy anyway.
To: Turn up volume
Press: F10
To: Turn down volume
Press: F9
To: Mute volume
Press: F8
To: Open Messenger in Media Center
Press: CTRL+N
To: Display the Help window
Press: F1
To: Display an additional menu of actions for a page or item that is selected
Press: CTRL+D
To: Go in and go out of windowed mode
Press: ALT+ENTER
To: Move left, right, up, or down
Press: ARROW KEYS
To: Go to the previous page
Press: PAGE UP
To: Go to the next page
Press: PAGE DOWN
To: Go to the last item in a list
Press: END
To: Go to the first item in a list
Press: HOME
To: Go back to the previous screen
Press: BACKSPACE
To: Accept the selection
Press: ENTER
To: Close Media Center
Press: ALT+F4
To: Open Media Center or return to the Media Center Start menu
Press: Windows Key+ALT+ENTER
To: Go to the previous channel
Press: PAGE DOWN
To: Go to the next channel
Press: PAGE UP
To: Skip forward 30 second while watching TV
Press: CTRL+F
To: Skip back 7 seconds while watching TV
Press: CTRL+B
To: Fast forward live TV or recorded TV
Press: CTRL+SHIFT+F
To: Rewind live TV or recorded TV
Press: CTRL+SHIFT+B
To: Play live TV or recorded TV
Press: CTRL+SHIFT+P
To: Stop recording or stop playing a TV show
Press: CTRL+SHIFT+S
To: Pause or resume live TV or recorded TV
Press: CTRL+P
To: Record a TV show
Press: CTRL+R
To: Go to live TV
Press: CTRL+T
To: Go to the Guide
Press: CTRL+G
To: Go to Recorded TV
Press: CTRL+O
To: Go to My TV
Press: CTRL+SHIFT+T
To: Copy a CD
Press: CTRL+R
To: Fast forward a song
Press: CTRL+SHIFT+F
To: Skip to the next song
Press: CTRL+F
To: Replay an audio file or song
Press: CTRL+B
To: Stop an audio file or song
Press: CTRL+SHIFT+S
To: Pause an audio file or song
Press: CTRL+P
To: Play an audio file or song
Press: CTRL+SHIFT+P
To: Go to My Music
Press: CTRL+M
To: Skip forward
Press: CTRL+F
To: Skip back
Press: CTRL+B
To: Resume playing radio
Press: CTRL+SHIFT+P
To: Stop live radio
Press: CTRL+SHIFT+S
To: Pause or resume playing live radio
Press: CTRL+P
To: Go to Radio
Press: CTRL+A
To: Zoom a picture in full-screen mode
Press: ENTER
To: Skip forward to the next picture
Press: RIGHT ARROW
To: Skip back to the previous picture
Press: LEFT ARROW
To: Pause a slide show
Press: CTRL+P
To: Stop a slide show
Press: CTRL+SHIFT+S
To: Play a slide show
Press: CTRL+SHIFT+P
To: Go to My Pictures
Press: CTRL+I
To: Skip forward 30 seconds in a video
Press: CTRL+F
To: Skip back 7 seconds in a video
Press: CTRL+B
To: Fast forward a video
Press: CTRL+SHIFT+F
To: Rewind a video
Press: CTRL+SHIFT+B
To: Stop playing a video
Press: CTRL+SHIFT+S
To: Pause or resume a video
Press: CTRL+P
To: Play a video
Press: CTRL+SHIFT+P
To: Go to My Videos
Press: CTRL+E
To: Change the DVD subtitles selection
Press: CTRL+U
To: Change the DVD audio selection
Press: CTRL+SHIFT+A
To: Change the DVD angle
Press: ARROW KEYS
To: Skip forward or go to the next chapter
Press: CTRL+F
To: Skip back or go to the previous chapter
Press: CTRL+B
To: Fast forward
Press: CTRL+SHIFT+F
To: Rewind
Press: CTRL+SHIFT+B
To: Stop a DVD
Press: CTRL+SHIFT+S
To: Pause or resume playing a DVD
Press: CTRL+P
To: Play a DVD
Press: CTRL+SHIFT+P
To: Go to the DVD menu
Press: CTRL+SHIFT+M
To: Turn closed captioning on or off
Press: CTRL+SHIFT+C
Enjoy!