Does the problem also occurs for 84.21?

I haven't had any reboots, and i've been using both the 81.98 and switched to 84.25 now.

Yes also occurs in 84.21 and the newest 84.43.

Ouch, are you using OpenGL output? It's OpenGL specific. I have a 6600 GT, obviously your mileage may vary.

To test the reboot, just start a game and alt-enter a few times. If you can do it at least 20 times or so, you should be safe. If your system spontaneously reboots, then you've got a problem.

Using ddraw or surface or anything else should be fine.

There may be more variables there. The problem may be chipset specific, m/b manufacturer specific, etc. I had very similar problem with ATI 9800 Pro, bluescreened and rebooted on Alt-Tab quite regularly. Then one day I had to replace power supply due to unrelated problem (faulty 3.3V line) and this problem disappeared as well. I guess not only 3.3V was faulty in that old p/s. BTW, did you check voltages reported by BIOS?

If the problem fixes using an earlier driver, then the problem lies in the drivers.

well unless the newer drivers enable some more power consuming operations on your videocard. 😉

Out of curiosity, are you using official drivers? Because I had some major problems on switching using fairly recent unofficial ones (DNA in particular), none of which have occurred since I cleaned up and started out with officials.

i'm working with Nvidia GForce 5200 FX AGP 8X or something like that....128 Mb memory i think on P4 3,0 Ghz 1Gb RAM Win XP prof.

i don't change the Nvidia drivers since...months...emm..don't remember but i've...81.98 version

i change from dosbox windowed...or fullscreened to desktop without problems with video mode changes

if somebody needs it...here's the 81.98 forceware drivers...
http://www.cyberscope-station.com/game_dungeo … nglish_whql.zip

Shed, are you actually using the OpenGL output in DOSBox? It only crashes using OpenGL, not ddraw or surface or anything else...

no, Darkfalz ... sorry, i don't catch it....but still not used OpenGL, usually i use "surface" or "DDraw"....but thanks for your response...

then it's OpenGL problem? i'll try OpenGL render and put here my own xperience with it....

I use OpenGL because it has triple buffering built into the driver, so I can get smooth scrolling without the impact of double buffering.