Fs9 starting problem

Several times recently I have tried to start FS9 but have only got the splash screen and then nothing, straight back to the desk top. It will have been running fine previously and I will have made no changes. Fortunately by doing a system restore I am always able to get back to normal. Another problem is that occasionally the computer spontaneously reboots, but this is always when the computer is idle.Has anybody had similar problems or have any suggestions?I've tried a few things, using Asus Probe to monitor temperature etc, I've run memtest, pagefile is set to system managed. The power supply is new and adequate for the system, the problems were there before I changed it.John