I only have 2 games installed on Steam, FONV and Skyrim. Both games run fine, but after steam has been loaded for about 3 or 4 hours, I get a Windows error saying I'm low on memory, and need to "close programs to prevent information loss". It is like I have a memory leak somewhere.

After about 2 hours of playing, the mouse response begins to get choppy, then soon afterwards I get the "Low Memory" error.... The only way to solve the problem is to reboot my machine.
If I do not load Steam, my machine normally runs for up to a week sometimes without a reboot. The only time I get the error is when playing either FONV or Skyrim.
(FONV I can live without, Skyrim I WANT to play!!!)

I have 12GB of ram installed, so I know that Steam + Skyrim is not taking up all my memory.

Any clues to why this would be happening?
Any tweaks I can try?

Well there could be more than just Steam causing the memory leak; your systems drivers, for instance. I've seen CCC cause this before with various installs (no particular version, just seems like a bad install).

During the time you don't load up Steam, do you play any other games or avoid using any other programs?

You could also try reinstalling Steam by deleting all the files EXCEPT Steam.exe and EXCEPT the folders, so Steam will re-download itself fresh.

I would think that if it were a driver causing the memory leak, it would surface at times when Steam isn't loaded. The only time I get the Low Memory error is after steam has been loaded for a couple hours.
I'm sure it is something in my set up, my niece loads Steam at system startup, and never closes it, it runs constantly on her machine. Also, I looked thru the Steam forums for any similar issues and didnt see anything there about this sort of thing.
I do run other memory intensive apps, I do quite a bit of graphics editing, and I run a couple games that are seriously memory hogs (heavily modded Civ4, heavily modded Oblivion, heavily modded FO3, etc), and never (never) get Low Memory errors with them....

I am hoping someone here has some ideas, I really don't want to create an account on the steam forums just to post one question.

As for re-downloading Steam, I live way out in the boonies, so I only have tier 1 DSL, which means it will take several hours to re-install steam, during which my computer will be basically unusable... I'll do that as a last resort.
I'm hopeing there is more options.

If Task Manager doesn't help you in locating the leaky process, try downloading http://technet.microsoft.com/en-us/sysinternals/bb896653. You can right-click its process list's column header to add GPU memory tracking to the list, too.

If even that doesn't show anything out of the ordinary, it could be a driver bug.

This might sound strange, since having 12Gb of ram, you'd be hard pressed to run out of use-able memory in a personal computer even if you tried.
While you shouldn't need to use virtual memory for swapping, what do you have it set to?

Re-installing Steam in the method I mentioned, by NOT deleting the folders inside the Steam folder, will keep all your games installed and make it so you don't have to re-download them. It's only when you uninstall Steam that you need to re-download all your games. Steam itself doesn't take up much room and should download fairly quickly even on Tier 1 DSL.

I'll check it next time it happens....

I have always heard you need to run at least a small swap file, so I am running a 4 GB page file. But yeah, like I said, I've never had memory issues like this before.

Ok, I'll do this later tonight when I'm not using the computer for anything else.

I just delete all the files in the root "Steam" folder EXCEPT Steam.exe?

A friend of mine was getting that memory message with 16gb of ram.
I cant remember the exact detail but it is a rare bug that affects a very small minority of users and is on the MS fix list, its some process that runs with the default desktop, handles the transparent task bar IIRC.
MS say to change your desktop to classic windows if it affects you until its fixed.

My friend set his desktop to classic windows and it went away.

I have the virtual memory turned off on my PC and no problems at all, I have 16gb ram now but had it like that with 8gb as well, no drama.

All FILES yes, FOLDERS and directories NO.

I'll try this out tonight.
Will let you know if it fixed it for me or not.

Very true, so we've eliminated that. Have to find out what background processes could be eating up resources, but 12Gb is a lot to eat up.
Do you have any special or high end desktop/theme profile?

You know I actually had and solved this problem myself since the first time I read this thread to now. What was happening was that when any program attempted to give the Secure Desktop UAC prompt (where the desktop fades into black), I would get "Out of Memory" or even worse, despite having plenty of memory available (RAM at 50% and VRAM at 30%). At one point my computer got so bad it just start flashing the faded desktop from Secure Desktop. First I did a clean install of my graphics drivers, as it was most likely a graphics issue. The clean install + multiple reboots (I had to do the clean install TWICE due to another issue) fixed the problem.

Are you sure its system memory , not talking about vram ? so i would like to ask what is your vram like alot or not alot ?

I thought that setting my desktop to Classic had solved the problem, left steam running overnight, and this morning when I got up, the "Out of Memory" error had popped up.
I went in to task manager, and my memory was fine.... but I had no sound. Rebooting fixed it.
I've been playing for about 3 hours this after noon, and memory is still looking good...
There is nothing like trying to troubleshoot an intermittent problem.
I don't know if the problem is fixed yet or not....


Nope, it's system memory.

This has happened to me as well with CCC

I just looked at Task Manager, "audiodg.exe" is what is eating all the memory...

I googled it, and obviously this is a known issue.

Any tips?

Do you have a creative sound card?

either way... a few fixes will come from knowing your audio property settings and probably disabling or reducing some of them.
As you said it's a known problem that for some causes a horrible conflict between audio hardware and software, most prominently with Creative cards.

Yeah, I have a Sound Blaster X-Fi Titanium Fatal1ty Pro card.
Are you saying you want to know my audio settings?
DXDiag Report?

I guess I'm puzzled because this problem has never manifested itself until I started running Steam.
So, it is a "conflict" between my sound card driver, a Windows process, and Steam?
And it isn't just with Creative products either, there are reports of this happening with other drivers as well (Via is one I recall specifically).

Since it takes hours for the problem to surface, it is going to be a several day process of sorting this out, IF it can even be resolved...

Hmm, try disabling all Sound and the Steam Voice options in Steam.

I don't see any way of disabling sound in Steam's "Steam>>Settings" menu.
Is there a ini/cfg file I can disable them in?

Huh, guess you can't disable Sound completely in Steam, or disable Voice communication entirely.

There is more than a few suggestions in this thread of fixes.
Take your pick and see if any work.
http://www.vistaheads.com/forums/microsoft-public-windows-vista-performance-maintenance/45950-audiodg-exe-fixed.html

As far as page files go, if you have enough RAM that you could not conceivably ever run out of memory, then you do not need to use a page file, and not using one may also increase performance slightly, because the operating system will do some amount of paging whether you're running out of memory or not. Also, even if you don't have an insane amount of RAM, if you're okay with the computer crashing when it occasionally does use up whatever RAM you have, then you can also disable the page file to save a little bit of performance. You need to understand, though, that if you run out of RAM and don't have a page file, the computer will completely freeze up and need to be rebooted. However, just before you run out of RAM, the system will run a full "scan" of the memory in an attempt to free anything it possibly can. Also, if you're running anything using managed languages like Java, C# (used for many games), and python, their own garbage collectors will do a final cleanup before resigning themselves to their fate. This occurs because most garbage collectors only do a partial clean-up operation during normal usage (for performance reasons), so there may be some objects that can be freed up with a full clean-up if the space is really needed.

I wish people would stop making out running without a pagefile improves performance, it does not. It only adds the fact if you run out of ram your computer panics.
If you weren't using a pagefile in the first place how did you expect it to be hindering you?
Seriously stop spreading it.

Understand the purpose behind it, then you'll realise just having a reasonable pagefile will infact improve things overall rather than not having one at all.
http://blogs.technet.com/b/markrussinovich/archive/2008/11/17/3155406.aspx