Can I backup and restore my Skyrim saves if I plan on installing a new OS? [duplicate]
The easiest way to do this is to just copy you save to an external drive, and put them back after having reinstalled the game. The savegames are located in C:\Documents and Settings\<Username>\Documents\My Games\Skyrim\Saves by default.
Also, they may be synchronized by the Steam Cloud. In this case, they'll automatically be restored after you install the game.
Your best bet would be to save your savegames, reinstall the system, Steam and Skyrim, and try to see if they are there. If not, you can restore them manually