I have installed a new laptop (Lenovo Z510) for dual boot Ubuntu 12.04 and Windows 7 64 bit. After several trials it now works, but I have a strange effect.
I always enter the Grub purple screen fine. Ubuntu always works. When I want to boot Windows however windows boots fine (I hear the Windows start sound) but I only see a blank, purple Grub like screen. I can operate Windows though, pressing three times the tab key and then enter shuts the PC down successfully.
Sometime a trick works like that: I press just the power key and the PC hibernates. When I switch on the PC afterward and choose Win7 in Grub again everything is working fine, this time with working screen. However I had to find the trick does not always work - maybe whether it works or not is just random :-(
The workaround is quite dirty, what can I do to get rid of it?
Thanks for your help!