Mouse and Keyboard freeze

I have not done much troubleshooting lately, but when I was doing it fulltime, as was mentioned in a previous post, these kind of problems usually tend to be hardware related - power supply, memory, video card, CPU. If you don't have decent access to spare parts, I'd recommend taking the tower to a repair shop and have them swap out parts. Sometimes a long process, but if they know what they're doing it should not be too painful.