Major Windows Problems?

OK! So I have big problem. I have an HP Pavilion a1210n originally with windows xp. I upgraded it to 2.5gb RAM and well, use to be a 500GB HDD. It worked for about 3 or 4 weeks then I ran into problems. I turned it on one day and it told me "BOOT DISK ERROR. ENTER RECOVERY DATA". I assumed the HDD was corrupt and because that was what HP told me with "SMART" error. So I used my PATA/SATA bridge and the hdd came up fine! I I was able to recover everything! I tried a 320gb sata hdd and it told me the same thing. (the 500GB HDD was also Sata) I pluged in a 320GB PATA HDD and it told me "enter Operating System installation media to continue." I tried to reinstall windows 7 which was on the 500GB HDD and it would not show up the drive. I got a SATA to PATA adapter and put it on the original 500GB HDD and it showed the same error message. I changed the jumper and the solder points were touching the outer metal part of the hdd and the card shorted and the capacitors on the card blew up. Bad design I guess. So that was the end of that. The HDD still works. I had a Western Digital 1TB Sata HDD that I thought was bad because the mybook enclosure it was in would not work. I ripped the enclosure off and plugged in the hdd and it showed up. Meanwhile it takes 5 min to boot bios. I also do have a bunch of random windows documents on there and Im not sure if that could be the problem. I took it out and plugged it into my bridge and it did not work. I am trying to install windows 7 on it right now but it is taking forever.

So the above paragraph I want to know what to do next. Please Tell me.

Now onto my second question. Windows Vista can be installed on a PATA hard drive. I have a fully functioning PATA HDD and it regonizes just fine no problems with it. I have a Windows Vista Home Basic Product Key. Does anyone know of a place where I can download an iso? Installing Windows Vista is also an option I dont mind.

Overall I just want the computer to run some form of windows newer then windows xp. I have 2 windows 7 home product keys and one windows vista home basic product key. 10 Points to the one who helps the most.