Today I set up pretty-mode.el and found that the laptop had all of the Unicode fonts but the desktop did not. I ended up installing Arial Unicode MS as suggested by unicode.org, and that installed all of the missing fonts.
If you have Microsoft Office 2000 and newer versions, you can get the Arial Unicode MS font, which is the most complete. To get it, insert the Office CD, and do a custom install. Choose Add or Remove Features. Click the (+) next to Office Tools, then International Support, then the Universal Font icon, and choose the installation option you want.