Jailbreak and Computer issues

Yesterday I jailbroke my iPhone 4 and have not had the greatest results. Something went wrong when adding a repo to cydia and it never worked for me. I am getting a malformed line error. When I went to try and fix it by unjailbreaking it, my pc crashed and now will not boot up. My dell inspiron had blue lines on the startup screen and crashed during boot. According to some research on the net this was caused by the video card. So, I tried to the onboard video card and the computer still crashes during boot. Then I formated the hard drive and tried to reinstall windows 7 and it crashed during reinstall. At this point I have pretty much ruled everything out except a hardware issue. I guess it might be the motherboard itself. I really don't know what I should do about it. Now I am transfering purchases to my laptop and going to try a restore on my phone to see if I can get that to unjailbreak my phone and possibly restore it to where it was before. I must admit I am a little hesitant to redo my jailbreak but I am thinking I will. Let me know if you have any suggestions.