That's just plain stupid. Tell your friend to save some money and get something better. It doesn't have to be fast, but get some new, higher quality parts in there. When I first started building PC's, I used to do stuff like that and had nothing but problems with Windows and drivers and just about anything else that could go wrong. Trust me, it's worth the extra money. If a friend told me they wanted a computer for less than $100, I would direct them to goodwill or the local dump.
EDIT: Sorry, didn't want to appear mean, but I am completely serious.