I've been using my toshiba laptop for 2 years now and i want to reformat. how will i do it?

Several ways:
1) boot with floppy with o/s(opeating system) with the program FDISK.EXE. & format.com. upon booting up,
1st:: from the A: >PROMPT [type] C: and hit ENTER (or the RETURN ) [type] DIR (thats short for DIRECTORY) note:: U MUST see the directory that is on the C: DRIVE or you are running the wrong o/s [operating system]
Go back to the A: drive ( A: [ENTER])
Run fdisk.exe There are several #s (1-4) pick the # that lets u see the "type" of format u have, take note of any special name that was given the H/D, If u have more then one PARTATION( A drive within a drive)NOTE THE NAME!
" ESCAPE" to main menu.pick the # that takes u to "DELETE".There is a 'submenu' to delete the main H/D or delete the partation[NOTE:: if you have a PARTATION, you MUST delete it 1st."ESCAPE" (u will be going back to the 'main menu' ) chooze "DELETE" again, SUBMENU, delete H/D
REBOOT........U won't be able to "SEE" the h/d after this. From A:>FORMAT.COM c:\ u