Cubase Studio 5 stops while recording

Ok, I just did the legacy driver mode and no success. same results, actually, it is happening quicker. I only get a few measures and then the recording fails. I have restarted the PC several times. Reinstalled the latest software for saffire pro 40. I am also stumped.
I have my PC with NO CPU throttling or restrictions. Set with running on the fastest possible. I disable even all the instant messagings, email/outlook, anti-virus. Only run Cubase and this web browser. I don’t really want to go into the BIOS as this pc was purchased just for media. I specially purchased the media package for this pc. (Extra RAM, Memory, Grafix, Hard disk and so on. So, I don’t know how this can be the prob when I know people running cubase 5 on a much older and way slower systems. But, then again…who knows.
I am going slightly mad.
I will take a break for awhile, going to watch some friends of mine and their bands play tonight. Try to start fresh in the morning and hopefully solve this.
Thanks for all of your patience and help.
Back later with a more refreshed mind…hopefully