M1710 LCD not recognised

Brand new XPS M1710, did a fresh install, everything was going smoothly until the system contracted a virus; "W32/Rbot-AJA" over our home network. AvastAV was installed on the laptop and alerted to virus discovery however could not delete the file. Next boot the laptop display remained blank until windows booted (no dell startup logo or loading windows logo) and took considerably longer to boot than usual.

Performed a system restore to a point just after windows installation. LCD now does not function at all (remains blank permanently) however an external LCD can be used. Diagnostic utilities run from dell diagnostic partition at boot time perform all tests but LCD test fails as it expects user input after displaying colour patterns on the screen (because I can't tell when to provide input) and then for some reason the LCD turns on when the utility asks to 'Continue testing, abort testing or Retry the LCD test' after the test has timed out waiting for user input, and displays the diagnostic utility as normal on the laptop LCD. So this proves the LCD does indeed still work, it's just not recognised as the main/primary display for the system. Upon exiting the diagnostic utility the LCD turns off again and remains blank.

Reinstallation of Windows XP (using the external monitor) has not rectified the problem and appears the external monitor is now set as the default monitor. Settings in the BIOS show that the screen type is a 17" Wide UXGA but the Native Resolution is "0 by 0" rather than 1920 x 1200 as it was when I received it.

Has anyone experienced this or anything similar? My laptop is now basically a desktop system because I can't use the laptop LCD!
Is there a way to change the primary display from my external LCD back to the internal laptop display? The nvidia control panel has an option to find displays attached, however it doesn't find the laptop display... I've sent an email to Dell tech support, although its a long weekend here so I can't expect a reply for a few days
Any help would be GREATLY appreciated!

It's a brand new laptop, there must be some other means of getting it to work apart from replacing the LCD, at least I hope so anyway.
Any one know if resetting the BIOS to factory settings or something along those lines would reset the LCD to the internal display? Is this even possibly without having to take apart the entire machine (I've got no idea how to reset a laptop's BIOS/CMOS)?

Looks like that's what I'll be doing. Just wanted to see if anyone here had any 'quick fix' remedies. Seems like a pretty unique problem though... unlucky for me I guess

At least I'm not alone any more! I can't recall the exact point at which mine stuffed up, although I know I tried a system restore and some point after that it happened. Dell has no idea what the 0 by 0 in the BIOS means and every time I've told one of the techs about this they just pass it off and either want to replace the LCD or the gfx card. Ive so far had the LCD, graphics card and the the mobo replaced and nothing fixed the problem and yes strangely enough replacing the mobo didn't fix the issue.

When you run the diagnostic test, if you just leave it running for ages it should try and run the LCD test during which it will ask for user input which could be those beeps you are hearing. When I left the system for a while the screen eventually turned on after it failed the LCD test (how hypocritical). When you exit the test the screen turns off again though, but that should prove to you whether the screen does in fact work at all.

Even stranger, I've tried booting the system without the hard drive connected and it still won't work, suggesting that it isn't a software problem. The only help I can offer you is to get a hacked driver from laptopvideo2go (all of the 90 series should work) and use that to find your laptop LCD. These drivers seem to have provisions for detecting internal and external displays unlike earlier nVidia driver releases. My internal LCD works with these drivers (just) but doesn't show any of the POST or windows loading screens, just turns on when Windows has booted. Apart from that, call Dell and if you are still within your warranty period you should be able to get a new machine as that's what they have offered me.