I am not looking to do anything spectacular with it, websurfing, dl music, watching movies, having a pc while I travel, the occassional cs 1.6 or dod 1.3. It should be able to handle all these tasks without any trouble.
First things first, back up all of your files and re-install Vista. I'm sure that some of your problems are caused by bloatware. If it still isn't performing adequately go out and buy a 2gb kit of RAM. 512mb is not enough for Vista to work effectively. Those two options should increase the performance.