Stumped I have a machine with an Asus M3n78 pro motherboard and 4GB RAM The system has been ...

[G+_Craig Strutt]

Stumped.  I have a machine with an Asus M3n78 pro motherboard and 4GB RAM.  The system has been running Windows XP for several years with no problems.   Pop in the Windows 7 Home Premium disk.  The system freezes at various points.  Most commonly at or immediately after the Starting windows screen with the colored screen.   I had a graphics card in the machine, which I removed and used the onboard graphics - same result.  I've updated the bios to the latest revision - same result.   I've unplugged any added equipment except for the keyboard / mouse (both USB) / monitor / hard drives - same result.  I've ordered new memory just to check.   Never run into this before and I'm STUMPED!

[G+_Paul Simard]

You don't mention if you used a clean install or an upgrade install.

[G+_Thomas Lambrecht]

The random crashing part makes me think it's the RAM. Can you try running "memtest86" (http://www.memtest86.com/). This can find a lot of memory errors.

[G+_Craig Strutt]

You can't upgrade XP, has to be clean.  Although it never got far enough to have that option.   I haven't run memtest, (though I've already ordered new RAM) but I'll try that today.  I did take a copy of Windows 7 ultra (which does try to install fresh within an already booted XP) and let it start.  It froze on the first re-boot at the same point.

[G+_Luke Militello]

This might be a stupid question depending on your tech level, so if that is the case, I apologize in advance. However, the symptoms you are describing can happen if the RAM cannot support the front side bus speeds expected; i.e. like using 1333MHz RAM when 1600MHz RAM is required. Are you sure you have the right speed RAM?

[G+_Craig Strutt]

Right speed RAM  PC2-6400 DDR2 from NVidia.   5-4-4@2.1volts  I've even gone into the bios and changed the voltage supplied to the RAM from the AUTO setting to 2.155volts.    Memtest86 runs clean on the quick tests.   No errors after 3.5 hours on the long tests.

[G+_Craig Strutt]

Just a thought.    Could be a bad power supply with incorrect voltage?  I haven't checked that.

[G+_Joshua Hamlett]

I would check the memory, even the  new memory, using memtest86. Memory errors can also turn out to be a problem with the motherboard, so test both the old and the new sticks, and swap slots, etc.

[G+_Craig Strutt]

New Memory won't arrive till NEXT week .   I'll post if I figure anything else new out.