Hi,
Pressing F8 during the black screen right after the BIOS screen should show you a menu for "Last known Good Configuration" or starting in the old Vista version. Can you access the operation system now?
It is always suggested to run the Windows 7 Upgrade Advisor to check if our system is ready for Windows 7, It can help you aviod potential issues with your hardware, devices, and installed programs.
http://www.microsoft.com/windows/windows-7/get/upgrade-advisor.aspx
You had better start by upgrading and/or resetting the BIOS settings to the default and disconnect all but the necessary devices (keyboard + maybe a mouse)and see if the installation comes through
