What type of keyboard and mouse are you using? Wireless? USB? PS/2?
If they are USB devices, make sure that they are connected only to usb 2.0 ports, not usb 3.0 ports.
To install windows, you should have only one ssd or hard drive connected to your system in addition to an optical drive if needed for the installation.
If I were installing windows onto a hard drive or ssd, to avioid win7 installation problems, I would have a completely empty "boot" drive.