As good Windows 7 seems to be, it has its perks, at least on my Laptop. I installed both 32 and 64 bit version of Windows 7 on M720R, and it had driver problems, on both architectures. There were more problem on 64 bit then on 32 bit.
Under 32-bit mode I was unable to use more then 4GB (obviously), but i couldn’t use inbuilt webcam either, other wise everything else was quite fine.
Under 64-bit mode I was unable to install SD-Card reader drivers, webcam drivers, and my beloved digital pen. I have been able to use bod SD-Card reader and Webcam under Vista64 without any problems. For SD-Card reader it seems that the driver needs to be re-signed, or I might need to enable developer mode [boot hack]. But Webcam and digital pen still stand without drivers.
After googling for couple of hours, I came to conclusion, I will not be able to use my inbuilt webcam, as there are no Windows 7 drivers for BisonCam [ALi Corp. 0402:5602], so I might move to Linux after all, as there are now drivers for this webcam for 2.6 kernal.