adrijan123,

When you reinstalled Windows did you install your drivers in the correct order?  Drivers need to be installed in the correct order for the hardware to perform correctly.

After a clean installation of the Microsoft® Windows 8/8.1 operating systems, you must install the following drivers / software packages: There is also a networking link below for resolving network and wireless issues.

How to resolve Wireless Networking issues on my Dell computer

How to Fix Limited Wi-Fi Connectivity Issue in Windows 8.1

• Chipset (System Devices)
• Display adapters
• Sound, video and game controllers
• IDE ATA/ATAPI controllers
• Imaging devices
• Keyboards
• Mice and other pointing devices
• Network/Wireless adapters
• Universal Serial Bus controllers

How to turn on or turn off WiFi/Bluetooth?

NOTE: There is no physical switch to enable/disable wireless. It has to be done through PC settings.

1. Launch Settings Charm and select Change PC settings.
2. Select Wireless from the left pane.
3. Under the Wireless devices option, move theWiFi/ Bluetooth slider to turn it off. Move the slider again to turn it on.

WARNING: You must install the Chipset driver first followed by the other system drivers. Reboot the system between installations.