I'm on vacation and on my cousin's laptop he has the same issue with his internet, but it only occurs after using the laptop for some time. It's also the only device on the network that this happens to.
My best guess is a problem with the laptop's wifi card.
As for the Date and Time, try setting it in the bios.
Don't reinstall an OS unless you ABSOLUTELY HAVE TOO!!! If you don't know what you are doing, you can get yourself into a worse situation.
Reinstalling an OS is easy but only when you know what you're doing.