Ok check those cables again and video card, I am beginning to think your monitor is going south for the winter or your video card, it works one time and then the next day it does not work, have you tried just the onboard VGA port ? that is your motherboards direct VGA port to your monitor ? and are you sure that when it did work Windows did not update it again ? your options right now are getting very slim as you have done everything possible and impossible known to mankind and the animal kingdom, I am thinking water now, do you have a boat that needs a new anchor...just saying
I am not sure if you have access to another computer to try the monitor on but I would suggest you do find one, I don't have a monitor like yours and those files and the install directions Dell has does not work, they are for when you are in Device Manager and select your monitor to do the update or roll back, maybe go there and let windows do the web search or add that set up file the one that is 2Kb and called setup file, I don't know why they even put that there on the Dell site, I tried on my computer and nothing showed up at all, I think your next step is to do the Dell Update search or have you done that already a zillion times, anyway give this a try and let Dell do a search and see if anything is suggested by them. I am including the manual for your monitor as well so look it over real good... the kitchen sink is looking pretty good now to throw in there, and are you on the same computer right now with the monitor and it is working ?
Now about that Registry Tweak whats that about, you shouldn't need to Tweak anything, can you direct me to where or what the exact message or site said ?
Leave your Registry alone and don't touch it or change it unless you know what your doing, but it is your computer and only my opinion as to the "do not touch"
Dell Auto Detect
Manual
Edit:
On that manual can you read Spanish or Portuguese ? my bad... but it seems any info for that monitor is in non-english, I will try to find an American standard version, till then use the Google translator
Edited by roadrage, 21 August 2015 - 04:00 PM.