Well it is definitely coming from your ATI Radeon card the Catalyst drivers, are you playing games by the way at the times it is doing that?
First have you gone to see if there are new updated drivers that you could get?

You can try this
Give this a shot
Right click-mouse over My Computer
Properties
Hardware(Tab)
Device Manager(button)
Click [+] next to System devices
right-mouse on CPU to AGP Controller (or whatever your controller is called, something like SiS AGP)
Update Driver(button)
Select Install from a list or specific location (Advanced)
Next(button)
Select Don't search. I will choose the driver to install.
Next(button)
Select PCI standard PCI-to-PCI bridge
Next(button)
Finish(button)
Reboot.

I would be willing to guess that it will start to cause crashes

Also you can see if you have the latests updates for .NET framework

Here is a link to AMD/ATI you might start looking here, especially some of those top topics.

and if you do not have this the latest catalyst driver then definitely try updating that FIRST from here:
Catalyst Drivers

Here is a link that might be useful: ATI

Thanks for your quick response, please bear with me I don't know much about computers (completely self taught, I learn a lot here reading the posts but learning and using are very different.......I'm a newbie.)

From trying to research the error I did find out (as you said) that it was related to the ATI Catalyst Driver-Video Card but when I tried to find driver updates at the ATI site I couldn't find the "Radeon Xpress 1100"

I'm not playing games when the error occurs. The ati2mtag error comes up several times just from starting the computer.........prior to doing anything except opening System Info. to view the error log.

I tried following your first set of instructions - going to Device Manager, Under System devices these controllers were listed:

Direct memory access controller
Microsoft ACPI-Compliant Embedded Controller
Programmable interrupt controller
+ Universal Serial Bus Controllers
.Standard Enhanced PCI to USB Host Controller
.Standard OpenHCD USB Host Controller
.Standard OpenHCD USB Host Controller

in that same section there are 6 entries for PCI standard PCI-to-PCI bridge

I was planning to post back here to find out which of those I was supposed to select but before doing that I made a mistake
oops.......right-moused on Microsoft ACPI-Compliant Embedded Controller..followed your steps but when I clicked next (expecting to find a box in which to choose the PCI standard PCI-to-PCI bridge) there was no next, a download started.........in seconds the "Completing the Hardware Update Wizard" box came up saying "The wizard has finished installing the software for: Microsoft ACPI-Compliant Embedded Controller....The hardware you installed will not work until you restart your computer. Click finish to close the wizard. (no other choices)

Restarted computer.....got a new error
Source - Service Control Manager Description - The Rogers Update Manager service hung on starting. * I don't think that's a problem but I am concerned about having installed unknown hardware.
I've no idea what I've just done or downloaded for that matter. In the vain hope of reversing what I'd done I Tried to do a System Restore.(thinking that would take care of my oops)....it looked like it was doing it, restarted and came up with "Could not restore to system checkpoint....no changes have been made" (System Restore has never worked for me in the past either)

I have Microsoft .NET Framework 3.0 Service Pack 1

Help, please!!!

ok what you did was simply have it check to see if there was a newer or updated version for that ACPI contoller and if it went and found one then that should be fine. Not sure how you managed to get there and do that though LOL So we will just not try that suggestion again LOL
Most of the items listed in there do have options to look for updated versions. So if I am understanding correctly that should not be a problem.

I put a link on my original post for your Catalyst drivers you might want to look there.

You really need to figure out why system restore has never worked for you on that pc. Tell me have you ever gone in and manually set a system restore point then gone back and tried to restore (in a short time period) to that created restore point?
I know that there are certain specific types of infections that disable system restore and some of the other features, have you used any of the good online scanners to see if perhaps you have an infection that has disabled things on your pc?
Trend Micro's FREE online virus scanner try that one.
And are you using superantispyware to scan?

Thanks, I'll assume updating controller is not a problem..LOL

I did run Trend Micro's online virus scanner......no potential threats found. Found out that in order to run System Restore I have to turn off my Norton/Symantec protection products. Ran a test System Restore and it was successful. Not using superantispyware but will look at that later.

Now back to my "ati2mtag error"....
I've never installed any drivers before so of course I read the "Installation Instructions" at the link for Catalyst drivers that you provided. Geez....there's a lot there.

It says (I think) to choose Option 1 or 2 to download (which one to choose??), then to remove all ATI and DAO programs from Add/Remove programs and to disable any antivirus, anti-spyware & any other system protection software before continuing. That sounds scary. Is it really that complicated? Please advise and no laughing at the computer twit here.........LOL

I do not think updating the ATI video drivers will help you here. I had this for months so off I went to ATI and downloaded the latest drivers - these are dated April 2008 by the way, if you are interested - but nothing changed. The computer worked with seemingly no ill affects as you also note. My card is a Radeon X800

Darn, I thought I had cured my issue but seeing your post I have just checked my event viewer and lo and behold the pest has returned. But only one instance on July 2 and none for 3 weeks prior.

OK I get 3 error messages together every time:-
1. The following drivers failed to load KLIF
2. The HID input service terminated with the following errors. The system cannot find the file specified
3. ati2mtag shows CRT invalid display type

I seem to have cured part of the problem because before those errors would either throw me off Firefox or reboot the computer. That no longer happens.

Probably got you more confused than before, sorry about that.

Sorry Owbist, to have made that particular pest raise it's head again. I wish my error only showed up once in awhile but when I check the error log, there it is
ati2mtag.........12c return failed
several times for each day I've used the laptop....it seems to be triggered by booting up???

I've searched online and found many instances of other people looking for a cure but none that have. At one time ATI had a note on their website that they were aware of the issue and would advise when they had a fix......but now there's no mention whatsoever of it.

Still hoping for a fix from the experts here.

According to your original post this notice causes no ill effects to your computer that you see. So why were you in the Event Viewer in the first place to have seen the notice? No reason you should not be in there of course but most users never go in that area. Where you having some kind of problem?

When you see this message is it on it's own or accompanied by other errors? As I said in my previous post mine always came with the other 2 but strangely 3 weeks ago there were 2 instances within 5 minutes of each other but no other error.

Do you see the 12c return failed message after double clicking on the error message and is there a link along with the notice? My ATI error never offered a link but the other 2 both did. Clicking those brought up a notice that no fix was available at this time.

Also when I would get kicked off Firefox or the computer rebooted the notice would appear to notify Microsoft, I did this often, even adding comments but there never was a fix.

Mine shows 'CRT invalid display type' but I have a Samsung LCD monitor.

Actually I was in the "error log" (Help and Support Ctr, Performance & Maintenance, Tools, Advanced System Info.)
over a year ago. I don't remember why, but that's when I noticed this repetitive error. Being a bit of a neat freak I googled the error trying to find a fix. Didn't find one. Every once in awhile I check and it's still there, EVERY DAY. You figured correctly, I had not been in the Event Viewer (had to google to find out how to get there), after reading your post I went there, "ati2mtag" Category "DAL" Event "43015" shows several times and when I double-click the error it just says "12c return failed" no link offered.

Looks like it's going to remain a mystery unless some genius provides an answer. I really was hoping to solve it.