Virus. Disable show hidden files

If you open Folder Option and check "Show hidden files and folders " you can not see hidden files.
To enable "Show hidden files and folders" feature follow below steps :
Go to Start menu -> Run ->type Regedit
Go to the following registry key:
HKEY_LOCAL_MACHINE->Microsoft -> Windows -> Current Version -> Explorer -> Advanced -> Folder -> Hidden -> SHOWALL.
Delete the value CheckedValue.
Create a new DWORD value called CheckedValue (same as above, except that the type is REG_DWORD).
Modify the value data to 1 (0×00000001). This should enable you to select the ‘Show hidden files and folders’ option without much problem.