Recently upgraded to Windows 7 - both mine and my wife's. Identical builds: Gigabyte GA-EP45-UD3L, 2x2GB RAM, Core2 E7500 (no OC). Both are running fine, except.......about 1/3 of the time, when my wife shuts down using Windows, it re-starts. Sometimes it will loop 4-5 times before finally stayin down. Any ideas???