I've unfortunately just experienced this issue. I've been running The Witched EE DC fine from Steam for a while now. Put over 20 hours into it, and other than the occasional crash, it was all good.
This morning I went to play and I got the "Minimum System Requirements Not Met" pop-up. I have no idea why. Nothing has changed with my hardware between the last time I played and this morning. The -force trick works, but the game is virtually unplayable when I load a game. The only "hardware" change would be that I hooked up a USB external hard drive to copy files the other day, but it's no longer connected and can't imagine that'd affect it.
I've uninstalled/re-installed the game, nothing. Uninstalled, reinstalled my video drivers, nothing. Turned off any virus protection or background programs (that again, ran fine a week ago), nothing.
I'm at a total loss here, and very sad. Any advice out there on how to get around this issue or discover what has changed materially in my system to make this a problem?
Firstly read: http://witcher.wikia...lp_on_the_forum
and attach that PCWizard report as instructed do attach the file ERRLOG.TXT from The Witcher/System folder ( if the game crashed )
Also you may want to run a full system scan with either malwarebytes or SUPERantispyware
Two other things come to mind would be to do a file verification check through Steam and a disc check