Knowing basic computer troubleshooting techniques is the key to help you fix this error. Luckily, the methods of fixing the qtcore4 dll issue shouldn't prove to be difficult to execute and should work in most cases. To prevent the qtcore4 dll issues from happening again take these following items in given order. I suggest you read through them to get an idea of what most likely applies to your situation.
1. Open Device Manager.
2. Follow the instructions in the preceding procedure to uninstall the device.
3. If you are prompted to restart the computer, follow these steps:
Plug in the device and then restart the computer. The device will be detected and reinstalled after Windows restarts.
Follow any instructions on-screen to complete installation.
4. If you are not prompted to restart the computer, follow these steps:
In Device Manager, in the Action menu, click Scan for hardware changes.
Follow the instructions on the screen.
1.Step by step click Start>Computer>Properties.
2.On the left pane Click on System protection.
3.Go to System Protection and click System Restore, then OK.