I installed Ubuntu 12.04 alongside Windows XP. The problem is that I cannot see the bootloader menu to choose XP anymore. My monitor shows the the message: Optimal Mode 1440x990 60Hz. After a while Ubuntu starts and I can see the Unity screen.
I have an onBoard Graffic: NVIDIA Cooporation C61 [Geforce 6100 nForce 405] (rev a2)
How can I fix that problem?