I had lOADS of problems

Question

I had lOADS of problems with my new PC (Vista) so my friend who was apparently a "computer expert" told me the best thing to do was KILL Vista and put on XP. As he builds his own PCs etc... I trusted him - FOOL THAT I AM!!!!!My PC will now not work as I've been told the components (ethernet connection and sound card - so far...) are Vista compatible and not XP so media player or broadband won't work.I've spoken to my "friend" who now doesn't know what to do which is really helpful. The company I bought the PC from will also not help as I've taken off Vista, therefore, vovoiding the warranty!PLEASE HELP ME.