i've seen a couple of posts on this, namely pointing to the RAID driver issue, so i thought i'd post my install comments as i have an m400 and have a stable environment.
before you instal anything on your toshiba m400, go and grab the RAID driver as pointed out in several posts across the internet. you can get it from here: RAID_M400. without this you will not be able to even start the setup on your hard disk. reason? let's not go into details -- bottom line: you need it.
once you have it here you go...
[note: there is an updated BIOS you may want to do first--not required for vista, but i always like having the latest. i did experience some BSODs with vista before (none yet with RC1, but i also have the updated BIOS...i can't confirm whether anything was fixed or not, just reporting that i haven't experienced the BSODs since.]
first, i'd recommend getting vista to DVD media. for me, that is so much easier to have, it's portable, it's not dependent upon a usb drive, etc. i just prefer that type of installation.
second, note that i am an os-purist. i prefer rebuilding a machine with a new os from scratch...not upgrading, not partitioning, etc. boot from dvd, format, install. i've always had best results using the philosophy and i'm not troubled with any left over os residue (yes, i'm not a trusting person for 'upgrades' and 'uninstalls').
plug in your usb key/drive where you unzipped the RAID drivers above. okay, once you have those out of the way, boot to your vista dvd media. you'll get to the setup screen on the m400 asking you where to put vista on your hard drive. here is where you'll notice you can't find your hard drive. hit F6 or click the 'Load Drivers' button on the setup screen. then navigate to the RAID driver folder and locate the KR10I folder (vista actually does a good job traversing through subtrees, but navigate to it anyway).
once that driver loads, you'll be able to see your drive (it may be marked Drive 1 [where Drive 0 is likely your USB drive/key]). just make sure you are picking/formatting the *right* hard disk.
here's where it is up to you -- partition or format...make your choice.
once you choose, let vista install -- on my machine (m400 w/2GB ram) it took about 20 minutes or so. once done you'll go through the normal stuff of setting up a user, time zone, etc. and then vista will start.
if your experience is like mine, the os will run great. you should have Aero ("Glass") effects out of the box with the Intel driver that is in-box with vista (v7.x.x.1053) but you'll notice a few things that may not be recognized yet.
before you do anything, run windows update. the biometric driver for the fingerprint reader will download as will the modem driver. okay, done. now you may notice still a few things out of skew...
- mechanical rotation (meaning when you actually move the tablet, it doesn't rotate the view)
- tablet pc buttons
- Function+F5 doesn't work
- 3 unrecognized devices in device manager: mass storage, unknown device 1, unknown device 2
let me shed some light on these. you should download the toshiba common modules first and install them. first the mass storage device is the texas instruments SD driver. one of the unknown devices is the HDD shock protection: DO NOT INSTALL THIS DRIVER, you will BSOD. the last unknown device is the bluetooth stuff.
you can get them all from here: M400 Vista drivers
for mechanical rotation, download the toshiba rotation utility.
for tablet pc buttons, download the toshiba tablet pc buttons.
for function+f5, download the toshiba Fn5 hotkey utility.
with all those, i have a great running system!