Sorry to bother you guys on this forum but i dont know hat to do about. I have bought a new lcd screen but strangly some games i cant play anymore, the modern games i have no problem with those mostly automaticly changed to its new resolution, but some older games i cant start anymore it gives an error message about direct x, strangly those games did normaly work on my older screen so I dont know why it doesnt work with the new one.

Which games aren't working?

Did you install and configure these games with the old display? If so, then they might now be configured to values that the new screen can't handle. Try resetting them (some games have separate setup utilities, other can be set to their default values by changing or removing ini files, other need a reinstall).

What graphics card have you got? Old games usually use 4:3 ratio exclusively. Whereas your new monitor is more likely to be 16:9 or 8:5.

So it could be that your monitor is not properly configured in your graphics card's settings (via control panel). Make sure that both Windows and your graphics card recognise your new monitor. Update or reinstall your drivers if need be.

Thanks for the reply most of them are older games on steam like Risen 1 and a newer game dungeon siege 3 maybe i look into folder if there is a setup. Witcher doesnt work either i see.

Oh, I see. Not exactly OLD games then? Well, it won't be an aspect ratio problem.

I'd start by doing a clean install of your graphics card drivers. Get the latest ones for your card online first. I'd also make sure that your monitor is being properly recognised by Windows. Make sure it's named and not just referred to as a generic plug and play monitor.

I'd also advise that you make sure that you install the Direct X that comes with games as sometimes unique files are included. But Steam does that automatically anyway.

It gives direct x problem but strangly some games work.

Kind of a long shot, but if you haven't installed the drivers for the new screen then you may want to give that a go.

From my own experience most newer panels (especially, 23" or above) cannot properly output 640X480 or below properly.

Well its been solved, I have looked at internet for the solution and I found out i need the hdmi to dvi cable and i bought it and the games worked . Only risen doesnt work and witcher 2 the menu is gone.
edit. I reinstalled witcher 2 and now is working perfectly fine.Everybody +1 for trying to help.