Senior moment there for me.
Below is a link to the download page for your model. When you select WinXP instead of the native Vista there are some drivers available, but not all. Look at the link and download what you can. Then you will need to try and find drivers for the other hardware. There is a TV tuner listed. The driver for that should be available from the manufacturer of that card.
HD sound may be a problem. Generic drivers may be available but the custom Acer software to run the sound may not work.
The Vista drivers will generally not work for WinXP.
As far as keeping Vista goes I too recommend that you NOT wipe the restore partition off the hard drive. You may very well want to restore back to Vista in the future.
There are TWO reason for that. Either to add value when disposing of the computer. Or to use as an upgrade platform for Windows 7. I think your will want Windows 7.
One other thing you should do is to create the restore disks. That costs you nothing but they are valuable later on.
forgot the link, here it is.