F300 means you are having oplock_not_granted error. This could be a result of damaged system file or virus/malware attack. The corrupted system file(s) will create missing or incorrectly associated files that are needed for the accurate operation of the application.
In order to solve this problem you may try following:
Run Registry Editor by typing regedit in the Search box. Open the HKEY_LOCAL_MACHINE folder. Open Software folder. Open "Microsoft" folder. Open "Windows" folder. Open "Currentversion" folder. Click on the Run folder. Click on the Error_oplock_not_granted file. Delete the file by pressing Delete Error_oplock_not_granted key. You can then reinstall the file on your PC.
Here is the path to follow: COMPUTER\HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS\CurrentVersion\Run
It is also possible that installing the latest drivers may remove this error.
There are many support utilities that help to remove this error. Check SpeedyPC Pro.
or
try this one www.mcrit.co.uk/scan-your-pc.
Hopefully it will solve your problem.