I keep tring to open the priates of carrabean file peices of eight and it keeps telling me it's an invalid file? what am I doing wrong?t rying to use it for a party invatation

No such file here ...

I think he's speaking about this one : http://www.dafont.com/pieces-of-eight.font

To download a font, you do right clic on "Download" and you choice "Save as...".
After, you unzip the downloaded ZIP file.

The font files have TTF or OTF extension. Be careful : some zip (like Piece of Eight) have some other files in the zip. Install only the TTF.

To know how to install a font, read the FAQ : http://www.dafont.com/fr/faq.php#win

thanks but I found the same file some where else not on this site and was able to download it with out an issue thanks so much

Oh come on, you know what font was meant. Please don't be too sarcastic, he or she might be dyslexic