windows 7 help

Hey everyone, first off thanks in advance. Well i have a Hp A1700N that had windows vista (32 bit) home premium. I have now added windows 7 home premium 32 bit and now i have lots of problems. The computer freezes ALL the time, i mean like a good 25 times a day. I restart with by pushing the blue power button, sometimes it will get stuck on the blue hp screen, or it will give me a boot disk error (most of the time), or even a disk read error and sometimes it gets stuck on the windows loading screen. The first time installing windows 7 i just did the upgrade and that gave me the same problems so i just did the full blown get rid of vista and install windows 7 but that didnt help at all. This computer had problems even with vista so could just something be wrong with the computer or can you guys point me into a direction to fix this thing? thanks again