I recently decided to upgrade the memory in my machine. My setup was as follows: ASUS P4S533 motherboard P4 2GHZ CPU 256MB DDR Ram (Samsung memory) Leadtek GeForce 3 Ti200 video card. 80 GB Hard Drive Sound Blaster Live Value I've been running that setup for over 6 months with no problems at all. After putting another 256 MB DDR with exactly the same memory chips on it(same code), after a couple of days i kept getting blue screens (stop messages) - IRQL-NOT-LESS-OR-EQUAL and others. Apparently that stop error can mean that the hardware is bad. The thing is, that i've successfully run the machine with each individual memory module for over a week with no problems. I've just put them back in together again and in the first couple of days, a couple of complete freezes when using Internet Explorer. Then today, blue screen again, same message as before. I find it hard to believe that the memory modules could be incompatible when they have identical memory chips on them. Can anyone suggest any ideas at all??

I have read in other forums that folks were experiencing the same problems, unfortunately I don't know why. But there is one thing I can mention; if you keep BSOD-ing your machine, eventually you may corrupt Windows which can lead to data loss, etc. The safest thing is to try to use the same brand and clockspeed.

What are your virtual memory settings? Have you booted in safe mode and let it run or tried to do something that causes BSOD to appear so that you can determine if device drivers and what not could be to blame. Certain programmers have made assumptions and don't check for unlimited potential memory and this can cause a problem with allocation routines and other code even though it doesn't sound like it makes sense, as a programmer, I can tell you that it does. The virtual memory issue may be helped (if that is what it is) by you setting the minimum and maximum size of the page file to the same size (if nothing else, this can improve performance). Also, you have a total of 512Mb RAM. Why not try disabling virtual memory altogether? borelli34

Can't be much help, but had similar problem recently. Added extra stick 256mb SDRAM that had identical manufacturer/specs etc. System would run with either stick but not both together. I traded the new stick for a different one from a friend's machine. No more errors. Weird.

I tried the virtual memory thing as well. With 256 MB i had it at about 600. I tried that with 512MB, also i lowered it to 300 with 512MB. I always have it set to the same min and max size. One thing i did note was when i changed it the first time, cleared virtual memory, created it again with 300MB, it was a few days before the BSOD's returned. Then again, could just be coincidence.

Some memory just doesn't like to play with other memory, just variations in the mfg process. I get that IRQ error once in a while myself, but it has gotten less frequent since I disabled the serial and parallel ports in the BIOS. Regarding disabling the page, DON'T. I have a full gig of memory, and still have a swap file that gets about 300 meg of usage out of a gig normally, and I still get "Low on virtual memory" popups.