Showing hidden files in Windows XP is easy. Just make sure you are making this change for a specific reason, because if you leave this option enabled, you could possible delete critical system files, making your system unusable.
1. Head to the control panel (Start->Settings->Control Panel) and select Folder Options.
2. In the “Folder Options” dialog box that opens, select the View tab.
3. Finally, select “Show hidden files and folders” and press OK.”
To reverse this (and to hide hidden files), go back to the “Folder Options” dialog box and uncheck the option you checked in step 3.