Using this Guide and a Video I was able to use 8GB of RAM in my CF-52P Win 7SP1 x86 Toughbook. There are also guides for Win 8 and Win 8.1.
It will also allow you to use almost 4GB instead of 3.1GB if you...
8GB RAM Win 7, Win 8, 8.1 x86
It will also allow you to use almost 4GB instead of 3.1GB if you...
8GB RAM Win 7, Win 8, 8.1 x86