Fonts like Cambria, Arial, & Courier New are very common.

A Web search will soon enough turn up the Windows system fonts.

Any font that is not listed as a Windows system font can probably be deleted fairly safely, though some Apps and many web pages use fonts other than the Windows system ones... You're unlikely to find many fonts specifically for Spanish, Russian, etc. Rather support for those languages is embedded in the regular fonts - including the system ones. Delete common non-system fonts at your own peril.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]