Vista - Uncorrectable memory error

Here is one I have never faced before. I week ago, I found the following error in the Event Viewer log:
Log name: System
Source: Application popup
Event ID: 1801
"The hardware has reported an uncorrectable memory error."
Next day, there were two, and then three, and four, increasing with one every day until I had 8. They only appear when I turn off the computer and shut down its power supply, and then start again. I do this every night. At normal cold or warm boot, these errors do not appear. The messages come first in the error log. I have run the Vista Memory Diagnostics Tool and almost all Dell Utility Tool available at booting. I do no longer think, this is a hardware error. I have run the Symantec on-line scanner and dito Kaspersky. I have run my own McAfee Virus Scanner. I have downloaded Malwarebytes and run it. Yet I cannot be sure, I do no longer think this is some nasty infection. After a hard fight between Malwarebytes and McAfee, leading to a return to older restore points, restoration of files from backup and uninstallation of Malwarebytes, my computer now runs as well as it ever has on Vista. This is less good than on XP, but OK, and I like the interface. Anyone having an idea on how to further investigate the reasons for these errors? Keep in mind, I am an ordinary, but bold, user.

Download memtest, Memtest86.com - Memory Diagnostic make a bootable cd/floppy and let it run for 8 hours. If your RAM is bad, or there are a few bad address ranges, this will let you know.

Thanks, I have made the CD. Sorry for a stupid question, how do I boot from it?

Change your bios to have the dvd-rom or cd-rom to boot first. I don't remember where that setting is in dell computer just look around.

Will do. I do not really think this is hardware related, but I guess it is a good idea to test this thouroughly first.

This guy could be you: Solved: Uncorrectable Memory Error - Tech Support Guy Forums Same error, same OEM.

Agreed, lets start with the most basic and simplest and move on. Make sure to let memtest run for a minimum of 8 hours. Don't shortchange yourself here. If your RAM turns out fine, then look into updating your bios. As far as I can tell these are the only two solutions to the problem.

Event ID 1801 may be logged in the System log on a computer that is running Windows Vista

You haven't messed with the bios' settings have you?

***edit***

Not sure how I forgot about this, but...

Hit the Windows logo key (on keyboard), then type reliability. Hit enter, elevate privileges and highlight 'reliability monitor'. The red circle with the x in it should have some details we can use to troubleshoot this. Find the error, list the problem(s).

Struggling with making a bootable DVD with the Iso image with help of Roxio. No success so far.

Reliability monitor provides no clue. I have had some problems though. Explorer.exe behaves strangely since a while back, problably from about the same time I started getting these errors. The taskbar disappears. I have tried various solutions recommended on the internet, like activating and deactivating the screen saver, changing screen resolution and so. It isn't just it has minimized below the screen. Only way to get it back is to stop the process in the task manager and then start it again. Desktop shortcuts do not disappear (until I kill the process). These problems leaves nothing in the event log or in the reliability monitor. This could be something else though, and I will try to uninstall some programs and re-install them again as it could be related to some of the plug-in icons.
The strange thing with the memory error is, it only occures after turning off the power supply, and that there is an extra every day. When backing on restore points, I went back to one again, now increased to two. How odd.. This is one of the reasons I suspect this may be soft ware related. Have not tampered with the BIOS (until today when I moved my DVD drive first in boot chain), and it is the latest verion. No overclocking.

Oh god... please get rid of Roxio. I could go on for days about their software... grab this instead: The Official ImgBurn Website You'll be a much happier and speedier camper.

Why are you turning off your power supply... just curious?

How old is this Vista install? Do you have a ton of patches prior to SP1?

I have no good excuse for turning the power off. Just that I have several cords plugged in to a safety switch and this one has a manual switch. As I have it, why not turn the power off when I go to bed?

Will make a new attempt to boot, and then, as this is likely to fail, go to bed. Good night and thanks for the help today.

sleep is for wussies...