I have 2 Dell Latitude E5420 Laptops that i recently installed Windows 10 pro 64 on them, installed around 10-01-16. This was a clean install and everything went well until today they both seem to crash (Lock up, no response from keys or mousepad) and I must hold power button down until the laptop shuts of and then I restart it and it will run fine for a few minutes and then freeze again. I did not use these laptops much since the install of Windows 10 so it is possible the problem could have existed for a few weeks. The laptops have intel i5 processors 4 and 6GB of ram 320GB HDD. Any suggestions would be appreciated.