Show hidden files option not getting retained

Why is "Show hidden files" option  not getting retained?
This is because, the update is not getting saved in registry because of the effect of virus. This can be fixed easily by following the steps below.

1. Type regedit in Run command
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
3. Delete the entry CheckedValue in the right pane by right clicking on the entry and click delete.
4. Create a new DWORD value entry by right clicking and clicking New-> DWORD value
5. Change the name of new dword to CheckedValue
6. Right click on the CheckedValue entry, hit modify and change value to 1. Hit OK.
7. Thats all. The problem is solved.