How do I know if I can delete a specific file?

• Check the date of the file (right-click on it and select Properties) - if it's recent, it's most likely being used.
• If the file is large, and you want to know if you can delete it, try renaming it or moving it to another directory before to see if everything still works before you delete it.
• No, you shouldn't delete WIN386.SWP (your swap file in Win95/98/Me) or PAGEFILE.SYS (your swap file in Windows 2000/2003/XP/Vista).