If you use the 533 FSB 2.8 E Prescott you can. Depends on your motherboard multipliers and memory and if it will support the Prescott core. I run mine at 3.6+ on air all day long and have had it up to 3.8 but it was just under heat specs so with better cooling it could easily go farther.
This is on the stock HSF at the default Vcore. I've had it up to 3.78 GHz but it was pushing 70 degrees C under load @ 1.5v Vcore. At this speed it runs at 3 degrees C over default 2.8 which is around 61.5C. I have the memory at 5x FSB. Ran it for 8 hours Prime95 and then played HL2 for 2...
Yes, I read everything you wrote, and you are coming off like a dick this being my first post on this forum. You really don't know anyone with a PCI-e slot? Can you get another PCI-e card and see if your system posts with it? Buy one and return it.
I thought it would have at least one (didn't know that Shuttle had no PCI)...I know the PSU should be fine. Try another rig.
My sig may say nOOb but I have been playing with hardware for some time. Sorry I wasn't exact on your shuttle model...I like towers better ;)