HI I have a quad core Inspiron 545 which I have had form new (2009).
The machine was completely reliable until a couple of months ago at which point it started generating frequent BSOD.
Ran hardware diagnostics and they reported hard drive errors.
Hard drive was replace with identical model. New drive was rebuild using dell supplied recovery disk.
Dell diagnostics reported no further errors.
At this point no further updates were made to O/S (Windows 7 Home Premium 64-bit).
In this state I can reliably crash the OS by running the Windows Experience Assessment.
(It gets as far a testing cpu/memory)
I have tried replacing the memory (4GB) and still the same results.
Both the original memory and the new memory were tested for 24 hours + using memtest 86 with no errors.
The hard drive has been tested using seagates dos-based tools (8 hours +) - no errors
If it were a hard drive issue I would have expected more issues during install or boot up but it works fine at that point.
I have tried a few clean installs. All produce the same results.
I have removed the video card and tried again just using the built in graphics controller - still crashes.
Finally I have tried with all devices diconnected except screen, keyboard, mouse and hard drive and still BSOD.
The BSOD is generating IRQL_NOT_LESS_OR_EQUAL errors but will vary sometimes.
Any thoughts as to the cause? Motherboard?