I use to get this a lot with the computer went to in a sleep mode,
I have now changed the power options for the network card so they no longer sleep and removed old network locations and reset windows firewall and its worked ok from then,
Now any time i do a reinstall i make sure to change the power options and never had a issue.
First off change the power options,
Do this on both wired and wireless connection,
Click on start and where is says start search type " device " you will see device mananger open this up and look for network adapters and click on the + sign to expand it, then right click on the adapter you want to change and click proerties then click on power manager tab and untick the box that says allow the computer to turn off this device to save power, do this for what ever connection you use ie wired or wireless, close all windows down,
Remove the old network locations,
Right click on the network icon on the bottom right by the clock,
Then click network and sharing center,
Click on the icon of the house or bench,
At this point turn off the router or unplug the cable,
Then click on merge or delete network locations,
Note that all the listed networks should show "not in use" one at a time click them and delete, once the list is empty close all windows down to the desktop,
Reset windows firewall,
Click on start and where is says start search type cmd at the top of the screen look for cmd right click on this and click run as administrator and a command windows will open enter this command and press enter,
You will get a message saying Ok. then reboot the comptuer,
Once fully loaded connect the cable or turn the router back on,
Give it a few mins and you will get asked to pick a network location ie home, office Ect pick home,
Fingers crossed that will be the end of the issue.