So there could be a number of things going on either with the Desktop Application specifically. (Interference, corruption etc…) or there is something on the system affecting its ability to obtain/apply updates to the game client. Given that you reinstalled Windows, I’d lean towards this being something with the router/modem. Given the fact that for a while resetting the router was helping also has me wanting to focus on that.
Try doing an extended power cycle on your system. Turn off all devices including the modem. Wait 30 minutes, turn on the modem, wait 5 minutes, turn on any network devices, wait 2 minutes, turn on your computer and try the game.
You can try switching your DNS settings to use a free public DNS servers instead of your ISPs Servers:
We do not have individual steps for specific modems or routers so if you need assistance accessing or updating the devices, contact the device maker/provider.
Sometimes firewall or routing software/hardware will have some advanced settings to prioritize and manage types of network traffic. Normally that is not an issue but we have seen situations where it can interfere with the delivery of the data for our games/voice chat.
Let’s try turning off these features:
RoG (ASUS Routers Only)
Security firewalls (Some ISP provided modems)
Not all devices will have these options and the steps for turning these functions off will be different depending on the make/model/software version of the devices and programs involved. If necessary look at the documentation for your security and routing products to find out how to turn these options off.
In some cases there is a corrupt or misconfigured setting within the router or modem. We cannot say what that might be offhand but the easiest way to resolve these conflicts would be to factory reset the router and/or modem.
You may need to look up your specific model for the steps on how to do this and in some rare cases you may need to have this done by the ISP. Feel free to reach out to them for assistance if necessary.
Do you have the ability to try a different computer on the same network? Or, the ability to try your current computer on a different network? This can help us determine if what you are experiencing is due to an network issue or something specifically with your system itself. Give it a shot and see what happens.
Try running your system in selective startup mode: https://battle.net/support/article/200483
Create a new administrator account: https://battle.net/support/article/34550
Once the account is created, shut down the computer, wait 60 seconds, restart, log into the new profile and try the app/client.
Let’s manually clear the Battlenet Desktop Application and all supporting data from the system. This will not remove existing game clients.
- Open file explorer/file manager (Right Click Windows Start)
- Navigate to the folder where the desktop application would normally be installed. Delete that folder if it exists (usually program files x86)
- Type the following into the address bar (not the search bar): %APPDATA% and press enter.
- Delete the Bnet and blizzard folders inside the appdata folder if they exist.
- Repeat steps 3 and 4 with %PROGRAMDATA% %LOCALAPPDATA% and %TEMP%
- Empty the recycle bin.
- Now reinstall the app to the C: Drive.
If that doesn’t solve the issue, then I recommend submitting a ticket with an msinfo attached for further investigation. (instructions for collecting that msinfo report will be on the form.)
Click your name at the top right of this page, click support, click contact support.