No Network Access

i have linovo z560 with windows 7 os. I had macffee antivirus and now its subscription is over so i have uninstalled this from my machine.
My problem is when i am using internet it suddenly goes down and shows "No Network Access", it shows the available networks in the lists and the one which i am connected in internet
connection lists. when i clicked on the network connection, it shows me limited access but i am not able to access the internet with the limited access.
when i click on troubleshoot the problem, machine gets hang while resolving problems. if i disconnect the internet connection and try to connect it shows me "windows was unable to connect to this network"
. And all the networks removes from the lists. If i restart the machine sometime it works. i am not aware why this issue started. i dont have old backup to restore and start working. i have some recent backup and i have resstored but it is not working.
Can someone give me direction to resolve the issue? i am very much frustrated with this issue and trying to resolve this issue since long time.
Thanks in Advance.

Make sure you have the latest wireless adapter installed. Try rebooting your router, sometimes a reboot of router will fix problems like that. Then see if there is any firmware updates for your router. Here's a link for your Lenovo drivers.

Drivers and software - IdeaPad Z560 Notebook


Noob Whisperer
Additionally, you mentioned that you have uninstalled McAfee, please followup that uninstall by using their vendor specific proprietary removal tool MCPR (McAfee Consumer product Removal) from here How to uninstall or reinstall supported McAfee products using the Consumer Products Removal tool (MCPR)
You didn't say what you had chosen as a replacement but if it wasn't MSE from here Spyware Protection | Free Spyware Protection | Microsoft Security Essentials I would suggest also removing whatever you chose and run the removal tool for that as well and consider, at least for the time being using Microsoft Security Essentials as your Anti Virus Anti Malware, generally speaking it is overall a bit more networking friendly than some of the others.
A list of some removal tools Security Software | SingularLabs

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