we upgraded the motherboard/cpu and ram on our pc it worked great fo a couple of mnths , a couple of weeks ago it did a coninuous beep like it was going to memory dump (blue screen)but froze and had to do a hard shut down, since then the pc wouldnt restart but froze on start up, eventually we tried to reinstall but it now get to completing instalation then freezes and wont complete, have had the new mb replaced and the cpu, have tried old ram and with and without graphics card even tried putting old psu back on all to no avail. now at a total loss on what to do to resolve windows 7 freezing on install,