I have built several PCs with Asus H81M-E, i5-4440, 8GB RAM and Chronos 120GB SSD, running Win 7.1. Many of them work fine, but after some weeks, some refuse to find the SSD on startup, just going to bios (which is what happens with this Mbd if the boot device is not found). If I then do a restart, the system sometimes boots ok, but sometimes it doesn't. I've tried changing the RAM, CPU, PSU and even the SATA cables. Mbd settings are at defaults and nothing is running too hot. Any suggestions please?