Indications:
Hidden files and folders missing in Vista
“Show hidden files and folders” option not working in Vista
“Show hidden files and folders” radio button changes disappear when closing the dialog box.
Reason :
Due to some virus malware attack in your system registry
Solution:
Even after you selected “Show hidden files and folders” radio button in folder option, if you can not see your hidden files and folders, Fix the registry by merging this registry file.

Download the registry file here. After downloading just Right Click on the registry file and select Merge as an Administrator. Now you can reconfigure Folder options in Vista and solve Hidden files missing in Vista problem.
If ‘Show hidden files and folders’ option missing in Folder Option it self missing in Vista , then you can use below method to fix the issue.
Got to Registry Editor in Vista ( Run – Regedit) , then go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden,
then Right Click on Type > Modify, Change value data to ‘ group ‘ .
Press OK then exit. Now you will be able to see ‘Show hidden files and folders’ in Folder Option.
Hidden files missing in Vista – find out the registry keys causing problem



