Re-installing Windows Vista x64 Media Center

Just as we were settling down to watch TV on Sunday night, our HTPC (which runs Vista Media Center) decided to stop working. After installing some updates, Media Center gave a "component registration failure" error whenever we tried to watch either live or recorded TV.  After several attempts at fixing it, I decided to re-install Windows Vista (this was something I'd been planning to do for a while because Vista had swallowed up almost all of the system drive on which it was installed).  Here are some notes on installing Vista on my HTPC.  Our hardware includes:

• TerraTec Cinergy 2400i DT dual DVB-T tuner card
• Biostar TA690G AM2 motherboard with AMD 690G chipset, PCI-E, Realtek RTL8111B ethernet, ATI Radeon X1250 integrated graphics with composite (YPbPr) video output and Realtek ALC888 audio (with digital S/PDIF output)
• PAL Panasonic CRT TV connected to HTPC via YPbPr composite

Here's what worked:

1. I wouldn't bother saving anything from the previous install; except perhaps making a note of which TV programs you want to automatically record (I had saved everything from C:\ProgramData\Microsoft\eHome\ (about 600 MBytes) but I didn't need any of this data.  All of our TV recordings are on a separate partition and I just told MCE to add that folder to its "Recorded TV folder watch list".  We manually re-entered all the programs we want to record.)
2. Do a clean re-install from the Vista DVD
3. Install all updates using Automatic Update (I tried installing Service Pack 1 manually but it failed several times, even after I installed the "readiness checker"... so just let automatic update do its thing... although it does take several hours and multiple re-boots)
4. For the ATI Radeon, ethernet and audio, I just let Automatic Update install the relevant drives from the "recommended updates". (In the past I spent a while tinkering with various ATI drivers to get the best signal on our YPbPr component output. It turns out I needn't have bothered: the driver installed by Automatic Update appears to work fine for YPbPr).
5. For the TerratTec Cinergy 2400i tuner, I installed driver 1.1.0.283a.  I tried to install 1.1.0.284 but installation failed.
6. Setup the "sleep settings" so that the machine goes to sleep after, say, 20 minutes (it wont sleep while you're watching TV but it will sleep if you leave it idle for 20 minutes... good for saving power).