Infections in virus scan

Infections in virus scan
When I scan my laptop, i find infections in MBR , ntoskrnl.exe, shell32.dll, user32.dll, kernel32.dll by AVG. In the result, it shows no threats. please help.

This fdisk command will allow you to recreate the Master Boot Record or MBR. Although this can be dangerous, it is a quick way to fix many boot issues... if you know what you are doing.
1. Click Start
2. Click Run
3. Type CMD and hit ENTER
4. From this dos box command line:

FDISK /MBR
This rebuilds the boot sector of the first bootable hard disk based on current disk structure. The partition table information should not be altered.

This is usually used to repair a damaged, corrupted, or infected master boot record.