if u have lost access to the folder options completely due to a virus or trogan u need to check this page just click on the link below or HERE
http://dennyphilip.blogspot.com/2007/08/no-folder-options.html


You might know this but for those who do not know.
>press start go to control panel (in xp and vista press the classic view on ur left hand top corner)
double click Folder options alternatively open my computer open c: then click on options > folder options ( in vista it is from the organize button > folder and search options)[Update windows 7 users press Alt on your key board to acces your standard menu from there continue as per instructed ]
>click the view tab scroll down until u see the topic hidden files and folders tick or select the option show hidden files and folders (if u are searching for a virus select the option view protected operating system files select yes or ok)
press Apply then ok.
now the options should look like this.

For mac os (credit of this info goes to http://devnulled.com )
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I do not use mac os but thoght this might help
for this open the command line type as below

brandon$ defaults write com.apple.finder AppleShowAllFiles TRUE
brandon$ killall Finder

This should make those hidden files visible.
Hope u found this useful