I would say about 4 years old, but I have changed just about everything in the computer. New power supply, graphics cards, and ram.How old is your PC ?
I've upgraded many of my home PCs some work great, another had an issue with the App Store not working, another an issue with internet access on it's wireless card. Microsoft are releasing patches super quick and all but one PC works perfectly. I can't help but wonder if Windows 7 wasn't really the best!