Hi Nikola,
Thank you for contacting Microsoft Community.
I suggest you to follow the below methods and check if it helps.
Method 1: Try the steps from the below link and check if it helps:
http://windows.microsoft.com/en-US/windows-8/troubleshoot-problems-installing-updates
Method 2: Try to Disable Anti-Virus Program as below.
- Right click on the Anti-Virus icon on Task Bar
- Click on Disable.
Hope this information was helpful and do let us know if you need further assistance. We will be glad to assist.