I spent hours loading and reloading programs and files in this computer, Dell Optiplex 990 SFF PC, Intel Core i5 Processor, 16GB RAM, 2TB HDD. It worked fine for one day and then would not boot up at all. I notified Amazon, they sent me  a replacement, I again spent hours loading and reloading programs and files on the replacement, it worded fine for three days and then the same thing, it would not boot up. I sent it back and purchased a new Dell.