My LCD wont work on pc "unsupported" message ?

I have a bought a new soniq qv191lc model LCD screen which i have connected to my pc ! The screen works on bootup and show the winodws logo and then usually where the blue wingows login screen shows up the , the LCD screen goes blank and with a "unsupported" message on it ??? Now if I boot up normally with my crt monitor plugged in and login onto Desktop, I can unplug the crt then plug in the lcd monitor and it will work on all resolutions and refresh rates ! why wont my lcd work on normal boot ????wtf

 

Set the resolution dictated by your monitor as native and refresh rate at 60 and try a boot sequence. If that fails lower the resolution see if your monitor has a driver and load it.