I started with a 32 bit version of ITunes and now it has changed to 64 bit and now it will not open and play anthing how can I fix it or do I just through it away and buy a zume

I just downloaded the latest 10.x.x copy of iTuness and I cant get it to run. I have purcased an HP G72 Laptop and it runs 64 bit It was running the 32 bit just fine untill last night. I am affrade to remove it and end up haveing to start from scrach with the 32 bit cd and the 300+ music cde I owen and like to listen too. Is there a way to clean it up without looseing everything??

Larry Pike