I have bought a Netbook Aspire one and it is a bloody nightmare.
To be fair, it is the keyboard that is the problem. After using the key "R" which it prints normally it has a mind of it's own, varying from not printing anything else, to printing over another printed paragraph.
It is driving me mad....something is wrong with the "R" key.
Well not so much a "big gun", more of a Colt .45, but I would suggest you try 'Start-->Control Panel-->Accessibility Options' and under the keyboard tab ensure you don't have boxes checked for Sticky keys, Toggle keys, etc.
Other than that, do you have the problem in a particular Application (eg Word) or is the problem universal? If universal, then my feeling is your keyboard is kna****ed. Can you not take it back?