I was personally having an issue with installing Windows 7 Home Premium 64 bit on my 3 year old Toshiba Satellite L305D-S5934 laptop. I have found the culprit and fix, so I am hoping this post will help anyone with the same issue. This should work on most Toshiba laptops, but I cannot guarantee it.
I was receiving BSOD after the install every time I fired up the laptop. Frustrated I spent hours of research on what the issue was. I was told everything from my hard drive, video card, processor, and memory was incompatible or failed. I was confused because I could reload vista with no issue. So through my own digging around the Toshiba website it turns out that the BIOS that was shipped with the laptop was outdated and would not support Windows 7. They actual had a new BIOS release that made all the required changes to support a full operational Windows 7 install.
Go to the Toshiba website and download and install the BIOS while running Vista, then afterwards you can run the upgrade or clean install of Windows 7. You will need to download and run the required Toshiba laptop drivers
following the install. You will also have to visit the Synaptics website to download and install the driver
for the touchpad scrolling.
I hope this helps, it got me up and running no problems.