What kind of laptops do ISS astronauts use?

 ThinkPad is the only laptop certified for use on the International Space Station (ISS).

• ThinkPads lapts have been used aboard the International Space Station since 1998.

• ThinkPads laptops have been on every NASA Shuttle space flight since 1995, when the ThinkPad 755 blasted off with the crew.

• ThinkPad laptops are used by all the major world space agencies (e.g., JAXA, ESA) thanks to their partnership with NASA.

• Some tests ThinkPads laptops have to pass before they lift off: radiation testing, off-gas testing, thermal testing, fire & fire suppression.

• Number of ThinkPads laptops aboard the International Space Station: more than 60.

• Number of NASA shuttle flights that have lifted off with ThinkPads aboard: more than 50.

and this link is about laptop software: astronauts in future will use Debian 6 moving from Windows and Scientific Linux