If you have a Toshiba Satellite manufactured in 2006 or previous years Toshiba does not provide support for installation. The second digit of the SN is the indicator. If it is a 6 or less you have an older Toshiba. If Windows XP is installed, to upgrade to Windows 7, a clean install is required. If it has been upgraded to Vista, Windows 7 can be installed over Vista. The main problem that you will run in to may be like that confronting me on a Satellite P105-S9722(nfg 2006). Toshiba used a RAID driver(KR10N.sys) on this machine. Windows 7 installation will stop when installing over Vista. Just remove KR10N.sys from the Windows/System32/Drivers directory and Windows 7 will install. After installation obtain the NVIDIA 7900 driver from the NVIDIA site directly. The Microsoft Update Driver for the 7900 may not work. The only other reported problem has been sound. I did not have that problem as I used Driver Robot to obtain updates for all other drivers. I hope this is of help to those who have an older Toshiba. TRS2004, TRS2006, TC1-2, TS2009 with multiple SP's work fine.
Charles
Charles