Originally Posted by Tazdunord
When i use DTD Calculator, i see in the registry DTD_1 (FA 1C 00 72 51 D0 1E 20 6E 28 55 00 00 00 00 00 00 1E) and TotalDTDCount (1).
Which keys? As Wo0zy indicated, some may be getting filled out which have no effect. Also, it should have "37 01" at the end, after "1E". Finally, please change it to
FA 1C FE 74 41 D0 1E 20 6E 28 55 00 00 00 00 00 00 1E
This is very important, as it's possible your BIOS is forbidding 1280x720, and since this is 1278x720 the restriction would go away.
Ensure that you're "extending" the monitor rather than cloning it from your laptop display. In XP, the checkbox for "Extending" is in the Display Properties. Not sure where it is in Vista, but it should be similar.
After reboot, the only resolution i can choose for the projector is 800x600 .
I didn't find "Hide Modes that this monitor cannot display" (Vista Home Premium).
On XP it's under Advanced | Monitor. Anyone with Vista know where it is there?
Do you have Powerstrip installed? If so, uninstall that bad boy. It mucks with getting the registry working properly. Do you have a driver file like a monitor.inf installed for your monitor? De-install; generally speaking, those files only provide restrictions, not capabilities.
If all else fails, roll back to 15.6.x drivers and see if those work. 800x600 default resolution weirdness began on 15.7 and this may be a residual effect.