I have around 20 computer that are all the same model hp dc7100 and they are all clones. -exact same image. All my monitors are also the same acer p191w.
Why does window XP sometimes detect the screen as "standart screen" (this prevents me from choosing the correct resolution) and sometimes as "plug and play" monitor at first boot?
When windows first has decided that it is a "standart screen", I do not know how to correct it!?
If all the monitors and devices are the same, and some systems are detecting the monitor correctly but not others, this is likely a bug in the monitor driver.
Can you reproduce the problem by plugging in and unplugging the monitor? What specific steps can you provide that reproduce the problem?
In other words, OK... say you have a system that is working fine and it detects the right monitor and resolution. Now, something happens between "now it's working" and a later point "now it's not working". What happens? It doesn't just magically re-detect it while you're sitting there using the computer, does it?
If it never detects it at all on certain systems, that's probably because you don't have the driver installed at all. The Acer website should have a driver download for the monitor which provides screen resolution information to the operating system so it knows how to scale the picture.
As a side note, Windows XP is in the very last stage of extended support by Microsoft, and is generally considered to be obsolete software. I very strongly recommend that you upgrade to GNU/Linux or, as a last resort, to a new version of Windows. Upgrading to basically any other (newer) operating system should resolve your problem.
