I am posting this so that others who may have one of the Sony VGX-XL1A Digital Living System PC can have another resource if they choose to upgrade it. Sony does not provide much support for Windows 7, so the information is scattered and mostly trial and error. I have performed this twice and it does work. This is only my experience:
Installing *Windows 7, 32Bit OS on Sony Digital Living System PC VGX-XL1A
1) Install Windows 7, 32 Bit OS.
2) Install **Windows XP Marvell Wireless Driver from Sony Website.
3) Connect to WiFi network. Windows 7 will install a large portion of the drivers automatically.
4) Install ***Windows Vista MPEG driver from the Sony website.
5) Install ***Windows Vista Audio (SigmaTel) HD drivers from Sony website.
6) For fiber optic or Coax digital output, configure you Audio Output Channel to S/PDIF.
7) If you have installed additional Tuner cards such as a Clear QAM, ATSC, install the MFG drivers. Windows may recognize and install a basic driver which does not recognize the ATSC digital tuner.
*Windows 7, 64bit can not be installed. The Marvell driver specifically will not load in this OS.
**For Windows XP drivers installation, you must set the program Compatibility to XP SP2.
***For Windows Vista drivers installation, you must set the program Compatibility to Vista SP2.
>>Some notes regarding upgrading and maximizing the VGX-XL1A service life.
-The default Memory is 256MB. Upgrade to 2GB (max supported amount), prior to attempting Windows 7 installation.
-The system has 4 RAID SATA ports, located on the Motherboard. Best performance result can be acquired by the install of an SSD for the primary hard drive. The load time and overall performance is greatly improved by this (40GB is enough). The 200GB will be a secondary for program recording. You will need to change the boot order in the BIOS.
-The NVidia graphics card is underpowered for HDTV recording and playback. Due to the power constrants of the Power Supply (300W), replacement choices must be carefully researched prior to installation. Many of the ATI 8400 based video cards in the market due fall just within these power specifications and do allow HDTV recording and playback.