Hi dyaro - Welcome to w7forum
Do you have any hardware plug into the computer, Scanners, printers, cameras, etc... . You can try unplugging everything and then try again. Once the install is finished then you can add them back and install the drivers for them then.
The only other thing I can think of that would be giving you troubles would be the Recovery Partition. Does you computer still have the Recovery Partition? If so you may have no choice but to remove it. I have heard others having this problem and the install went perfect afterward.