>>4190
I think these specs seem decent for the cost. The important notes:
-It has old i7 920 from year 2008 which gets beaten by some of the newer i5s so it's a bottle neck in the system. Considering that the cost of this build should be lower.
-The nVidia GTX 960 is a good modern GPU and the 4GB of VRAM is a good thing.
-16GB of DDR3 is bit too much. Most people won't in general need more than 8GBs. And more can be installed if needed to.
-Old budget motherboard for the old i7.
Summary: This is not ultra gaming PC. It's a decent mid range one with old CPU, good GPU and overkill amount of RAM. Rest of the components are more or less ok but I wouldn't go for old MSI X58 (it's a budget motherboard from ~2009) as a motherboard and especially not in this price range.
If you build your own for 800€ you'll get far better CPU, slightly better and newer chipset motherboard that performs better than the MSI one, same GPU and 8GBs or more RAM.
Verdict: Build your own. Compare options e.g. at pcpartpicker.com and ask questions in their community and in here. Another community that might or might not be able to help you can be found by googling Tek Syndicate.