Usually when virus hide files and it also remove folder options it is much difficult to get the files quickly if one is in hurry, although such virus can be removed manually (Read Remove EXE virus manually) ;

But I’m going to tell the the way in which you can UN-hide all the hidden files by on single command.

To apply this command follow the following steps

go to Start > Run > type cmd

Dos will open type cd.. (two to three time until only drive letter left)

now type the drive letter in which you want to Unhide the files lets suppose in my case its F:\

this will open the F: drive

Now type the following command attrib -r -a -s -h *.*

Press enter this command will un-hide all the hidden files in Drive F even its portable memory stick or usual hard disk