got the op sys not found black screen, so i put in another hdd to try and wala, worked like a champ. so i bought a new hard drive but went from 5400 rpm to 7200 rpm, now i cant install win7 on it? i tried from a usb, i burned a dvd copy, got a burned copy from some one else, so the usb would not install, the copy i burned will not install, but the borrowed copy gets all the way to "expandig windows files" hangs then new window sayscannot install required files,make sure all files required for install are available and restart instalation with error code 0x8007045d and i tried this several times,????