I have a Studio 1558 1week out of warranty, suddenly freezing several times per day. 

A snipped version of CPU-Z output is attached, System summary is:  i7 720Qm, Motherboard 0874P6, 6GB RAM, WIndows 7 x64,

BIOS is updated to A12, all drivers I can find are up to date, either through Dell support Centre or Windows update. I have run preboot assesment plus extended diagnostics including extended memory tests etc, no hardware error was detected. (CPU reached 98C duting a memtest, observed with HW Monitor)

Since the system freezes I dont get BDOS, or any dump files.

Any suggestions anyone?