I found this in a few different places around the 'net - hopefully it's helpful:

Show Hidden Program or System Files

Showing hidden files can come in handy?for example, say you've tried to delete everything from a floppy disk and the disk properties still indicate 100K of disk space is being used by hidden files.

• On the Tools menu in Windows Explorer, click Folder Options.
• Click the View tab.
• Under Hidden files and folders, click Show hidden files and folders.

Note: To access Windows Explorer, click Start, point to All Programs, and then click Windows Explorer.