I havent tried this as I aint got Vista yet - USE AT YOUR OWN RISK
Quote:
MSTN
know a lot of people were disappointed by the lack of a decent boot logo in Vista, so I’ve thrown together a tool that should simplify the process of creating the new high resolution boot logos! Your works of art need to be saved as 24-bit BMPs, and you’ll need to create them in two sizes: 800×600 and 1024×768. On my machine the boot logo always defaults to 1024×768, but I assume the 800×600 version automatically kicks in if your graphics card is rubbish 
Once you’ve selected your two images, just click File -> “Save Boot Screen File As…” and it will generate the logo file. To make the logo come up during boot, you’ll need to copy the file to the following folder:%windir%\System32\en-US
You’ll also need to make sure the /NOGUIBOOT option is enabled in the MSCONFIG tool, otherwise you’ll only get the old 16 colour boot screen. For full details, make sure you read the info during setup. IMPORTANT: It’s still beta and there may be bugs so use at your own risk, and make sure you backup first! Download
Vista Boot Logo Generator 1.1 (Freeware)
Only works on x86
