When using a touch panel with Vista Media Center, the playback control and scroll chevrons are not displayed until the screen is touch which does make it harder to navigate and control. There is however a simple registry edit that will ensure the controls are visible all the time making touch navigation and control much easier.  Look below for full details on how to edit these settings.
You may also download this file: http://www.origenae.com/support/download.php?FLIB=1&id=151

It contains 4 *.reg files that can be used to modify the above registry settings without having to find and edit the keys manually. Simply extract the files and right click on them individually then click 'Merge'. There are 2 sets of files, the _on files enable the above settings, the _off files restore back to the original setting (so you don’t need to Merge all the files, unless you are restoring the original settings). You will need administrator rights to apply these files.

These files have been tested with Vista SP1, but as with any registry modification, always backup just in case!

Two registry keys need to be edited, one for the toolbars and one for the navigation arrows.

1. Click start and run Registry Editor by typing 'regedit' in the start search box then clicking the application found.

2. Browse to HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Media Center\Capabilities and edit the key TBP by double clicking it

3. Change the value data from 0 to 1, then click OK

4. Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Settings\MCE.GlobalSettings and edit the key bindNavHintsToToolbars by double clicking it

5. Change the value data from 0 to 1, then click OK

6. Now when you open up Media Center, the navigation arrows and control will be visible even before you touch the screen, making control easier.