possible? yes.
easy? **** no!
and it would probably destroy the laptop.
of course you could terminal into the good computer with the ****ty computer. youd need a version of windows that supports terminal services though, i think xp pro does, as for vista and 7, depends on version. im not sure if the xp remote desktop is compatable with the equivalent on 7, but being pro it probibly supports it. you also need some kind of network, i use my wireless network, but for this application a nice gigabyte line would be useful even if its just a crossover cable.
i actually do this upstairs where my soldering table is, the laptop is not very powerful and has no usable storage. the only reason i use it is because it has serial and parallel ports, to program microcontrollers and stuff. but i store all my files on the computer downstairs. i only use the laptop when im working on electronics and need to pull datasheets off the net and get at code and run eagle cad on the more powerful comp. i use wireless and its sorta slow on the refresh, but it works.