I have a thinkpad T60 installed with Windows 7 and Ubuntu 12.04 without any problem. However, after I upgraded Ubuntu 12.04 to 12.10 (beta2) I found my Windows 7 was missing in the grub menu. I also tried fresh installation for Ubuntu 12.10 beta2 several times (with and without partition but the result was same (It was also very strange that the restart doesn't work). I also noticed that the installer (I burned a live DVD) could not detect Windows 7. Finally I decided to re-install 12.04 and Windows 7 came back again.
Could anybody please tell me what might be the problem?