Wi-Fi Sync and Home Sharing problems

I am running Windows 8, I have the last version of iTunes installed, I've got an iPhone 5s running iOS 7.1.2 and I face the following problem.

Basically, Wi-Fi Sync, Home Sharing and using Remote app to control iTunes on my PC sometimes stop working for no reason. What I mean is that if I can connect my iPhone to the PC and use all the wireless features and then I turn my PC off, when I turn it back on iTunes just cannot find the device.

The only thing that helped me was turning my router off and back on again but it is a tedious process and I can't do it every time I need to use iTunes.