Re: WiFi issue
If connecting to the modem with a cable works, then there are no issues with the broadband service itself.
Putting the machine into Sleep mode often confuses my Win 7 Netbook in the way you describe so I NEVER use Sleep mode.
When it happens, a hard reboot always solves the problem and gets wireless working again.
However as always, logic is the way to approach these things and elimination is the way to go.
So . . .
Do you have any other devices that use your WiFi broadband?
i.e. Kindles or other e-readers, smart phone, iPad or other tablet etc?
If so check if they are still working.
If they are then your problem is the computer. A
If they aren't then the problem is the router. B
For A, a reboot should solve the issue. Actually simply logging off and back on can often fix it. (I assume you have manually clicked on the network links and asked it to connect to your home network already)
For B, it's possible the wireless function has been disabled or the aerial has come detached (unlikely)
If so, go into router settings using your computer and look through the various menu options to find the wireless function. Ensure it is enabled.
Finally, make sure that your computer going into Sleep mode was the only thing that changed.
Has anything else changed or been updated recently? Any password changes? Any software updates etc?