You need to be careful with this. Formatting your laptop means several
1) You'll lose all data on the drive being formatted, so make
2) After formatting you'll need to install the drivers for your
system. Make sure you have all the necessary drivers before you do the
format. This will include the driver CD you may/may not have received
with your computer.
If you do not have the drivers, you can download it from Toshiba's site
(Click the "downloads" tab to view all downloads - then select your operating system you want to install in the drop-down above the downloads)
3) If you format you lose all the software installed on your operating
system. Check that you have all the installers of software currently
installed on your laptop. If you don't, it should be relatively easy to
find them by doing a quick google search.
Now that that's out of the way, here's how to format:
1) Insert the windows CD you want to install. Restart your machine
and boot from the CD (do this by pressing F12 while the laptop starts up and choose your CD-Rom when prompted). You'll need to 'press a key to boot from CD' as well after this selection.
2) Follow the steps of your installation until you're asked where to install windows. For example in Windows 7/Vista a box is displayed where all your drives are listed....press "Drive Options" at the bottom-right and click format drive. Make sure you have the correct drive selected in the box. In the case of Windows XP you'll select a drive in a DOS-like interface and press enter. Then you choose one of the options in the following screen(s) that would format the drive. (basically any option besides leaving the drive as is).
4) Follow the rest of the installation and let Windows complete installation.
5) Once the installation is done, and you've booted into windows, you need to install all the drivers and software you use. Start by installing the drivers (one by one) and following the instruction by each installation. Then install your software.