i have a hp model a6750f. mobo went bad and hp could not supply replacement. purchased used aspen ms-7548v1 and replaced. bios now says i have a model m9500f. thats ok as the specs are the same for either mobo and will take my amd4 processor. now i cannot get vista to load and got errors saying to insert my vista or recovery disc. recovery did not work either. tried to install a new w7 disc. during install it quit on one of the restarts. removed hard drive and had a friend test it and reformat it clean, all partitions. reinstalled w7 and it did the same thing. ran hp help from bios and got BIOHD-4 error. i suspect that a tattoo is keeping me from using the operating system. i have also tried to install unbuntu and it will not let that run either. all hp support wants to do is sell me a new system. any suggestions? i'm not real experienced here. thanks