When I connected my Acer AL2216W 22″ widescreen monitor to my HP 2510p notebook, I didn’t expect there to be problems. But there was a problem: For some reason, I was unable to set the resolution to 1680×1050, which is the monitor’s native resolution.

This took some more googling to find a solution. Here’s a short summary of what I found out:

1. Open the registry editor and do a Find on “DTD”.
2. Populate every occurence of TotalDTDCount with the number 1.
3. Populate every occurence of DTD_1 with the following string:

   21 39 90 30 62 1A 27 40 68 B0 36 00 D9 28 11 00 00 1C 37 01

   and be sure to keep searching until you are sure you got them all.

4. Reboot, and 1680×1050 should become available.

Now, if you need to set another resolution, things get a bit tricky.

You need to find out the correct DTD string (see step 3) for your resolution. That can be done using a small tool called MonInfo. How to do that and how to proceed is described in this article (it’s long but worth reading); I suggest you have a look at it