MS have just released an update to an old tweaking tool for XPMCE. It's updated for Vista and includes a whole bunch of tweaks. Source code is also included.
http://code.msdn.microsoft.com/tweakmc
Here's the summary:
TweakMC is a set of useful commands for Media Center Edition, adding additional flexibility to various areas of Media Center. The source code is included and can be used as a reference to create additional custom TweakMC settings.
The releases page contains download files (TweakMC executable, readme document, and source code project).
Below is a list of the settings included in TweakMC for Media Center. Refer to the Readme document for additional command details and the registry keys they correspond to.
General Settings
Display Wireless Passwords: When joining a wireless network, do you want to read the password as you enter it or do you want it to be hidden?
Overscan Adjustment Settings
Enable Overscan: Some televisions do not display the full Media Center user experience. Do you want Media Center to pull in critical UI elements?
Bottom Margin: How many units should Media Center pull in critical elements from the bottom of the screen?
Top Margin: How many units should Media Center pull in critical elements from the top of the screen?
Right Margin: How many units should Media Center pull in critical elements from the right of the screen?
Left Margin: How many units should Media Center pull in critical elements from the left of the screen?
Enable AddIn Debugging: AddIns start automatically when Media Center starts. Do you want to be prompted to attach a debugger when your AddIn is loaded?
Override the Current Screen Resolution: Media Center displays a warning if the current screen resolution will not run at an acceptable level based on your current video card. You should note that this determination is an estimate based on the information Media Center can gather about your video card. To prevent warnings from repeatedly displaying, enter your screen resolution(for example, 1920x1200 or 1024x768).
Toolbars Settings
Display Navigation Buttons: Do you want to display navigation buttons in different Media Center galleries and the Start screen when a toolbar for the two-foot experience is displayed?
Always Display Two-Foot Toolbars: This ensures that two-foot toolbars are displayed in all screens in Media Center except when video plays full screen, when visualizations are displaying as music plays, or when a slide show is playing.
DVD Settings
Enable DVD Library: Media Center has a DVD gallery with cover art and descriptions called DVD Library. Do you want to enable the DVD Library? This will remove the Play DVD tile and you will need to go to the DVD Library to start a DVD.
Autostart Enhanced DVD Content: Some DVDs include bonus content enhanced for Media Center. Do you want to automatically start the content?
DVD Notification Timeout: Enter the number of milliseconds that you want to view the notification that a DVD has been inserted and is about to automatically start playing. (1 second = 1000 milliseconds)
Search Depth: The DVD Library will search all locations that you have added in the DVD Library as well as your Videos directories. How many levels deep should it search for DVD content?
Search Network Locations: The DVD Library will search all locations that you have added to your My Videos space as well as locations added in the DVD Library. Should it include network shares and folders in its search?
Show Cache File Location: In the DVD Library when no metadata can be found for the current disc, the location of the cache file can be displayed on the DVD details page. You can edit this file to include any data that you would like to see displayed on the details page instead. Should the location of the cache file be displayed if there is no metadata?
Suppress Eject Prompt: When a 3rd party application (More Programs or Online Spotlight) tries to eject a disc, do you want a confirmation dialog?
TV Settings
Skip Forward Interval: Enter the number of milliseconds you want to skip forward when you press the skip button. (1 second = 1000 milliseconds)
Skip Back Interval: Enter the number of milliseconds you want to skip back when you press the replay button. (1 second = 1000 milliseconds)
No. of Most Viewed Channels: Enter the number of most viewed channels you want to see when you check the most viewed list in the TV guide
Storage Location for Recorded TV: Enter the path for the storage location for recorded TV.
Watched Folders for Recorded TV: If you have recorded TV stored in multiple locations enter the folder path below. You can enter one folder path for each line below. Example: C:\Recorded TV
Notification Before A Recording Starts: When you are watching TV a notification appears before the channel is changed to start a new recording. Enter the number of milliseconds to show this notification before Media Center changes the channel to begin the recording. (1 second = 1000 milliseconds)
Pre Recording Time: When you are Recording a show, the number of seconds for which Recording has to happen before the actual show time
Post Recording time: When you are Recording a show, the number of seconds for which Recording has to happen after the actual show time
More Info Panel Timeout: Enter the number of milliseconds to show the More Info panel while watching TV or DVD. (1 second = 1000 milliseconds)
Seek Bar Display Settings:
Display Timeout Settings
Seek Bar Timeout: Enter the number of milliseconds to show the paused seek bar while watching TV or DVD. (1 second = 1000 milliseconds)
Seek Bar REW/FWD Timeout: While watching TV or DVD pressing REW/FWD displays the seek bar. Enter the number of milliseconds to show the seek bar when transitioning from REW or FWD to normal playback while watching TV or DVD. (1 second = 1000 milliseconds)
Seek Bar Slow Motion Timeout: Enter the number of milliseconds to show the seek bar when video is in slow motion playback while watching TV or DVD. (1 second = 1000 milliseconds)
Time Formatting Settings
Ending Position Time Format: How would you like the ending time of recorded TV or a video to appear? (For example, assume video length of 8 hours, 53 minutes, 4 seconds. Then should it be displayed as 8:53:04, or 8:53 etc.)
Live TV Start Time Format: How would you like the starting time of a live show to appear? (For example, assume show started at 2:30:00 PM on November 2, 2006. Then should it be displayed as 2:30, or 2:30 PM, or Nov 2 2:30 etc.)
Live TV Stop Time Format: How would you like the ending time of a live show to appear? (For example, assume show ended at 2:30:00 PM on November 2, 2006. Then should it be displayed as 2:30, or 2:30 PM, or Nov 2 2:30 etc.)
Update Interval Settings
When Playing: Enter the number of milliseconds in between seek bar updates when playing.(1 second = 1000 milliseconds)
When Fast Forwarding: Enter the number of milliseconds in between seek bar updates when fast forwarding. (1 second = 1000 milliseconds)
When Rewinding: Enter the number of milliseconds in between seek bar updates when rewinding. (1 second = 1000 milliseconds)
Margins Settings
Horizontal Margins: Enter the number of units of space between the left screen edge and seek bar. (Unit size varies depending on resolution)
Vertical Margins: Enter the number of units of space between the top screen edge and seek bar. (Unit size varies depending on resolution)
Note: The following three settings require Administrator permissions.
Remote Control Settings
Enable Universal Remote Control: If Media Center does not respond properly to the OK button on your remote, enable universal remote support. Not all universal remotes require this though.
Set Remote Control ID: To enable your Media Center to respond to a specific remote control ID do the following; 1. Press and hold the DVD Menu key on the remote then press a number button (1-8) for 5 seconds. Remotes with visible LED signal indicators will blink twice to confirm the change. 2. Enter that same number below. 3. Save. 4. Restart the Media Center PC.
Note: To enable Media Center to respond to all remotes use the number 0.
TweakMC Extender Settings
Adjust Buffering Settings: Media Center Extender automatically optimizes its media buffering settings based upon the type of network connection. On some wireless networks, applying the wired network buffering settings can result in improved playback responsiveness but also might result in decreased video performance.
