My PC crashed recently and i lost a font that looks great on the website i'm building...
I need the font - Blippo Light SF
...& how come it disappeared from microsoft windows when my PC crashed?

Thanks

Second first ... it doesn't. Only when you reinstall Windows AND you only had the font in your Windows\Fonts directory (not really great wisdom) you will loose the font.

First: Contact your font vendor, explain the situation and ask for a copy. If you can show how and when you bought it, you probably will get the copy.

If all fails: Blippo Light SF ((c) 1990-1993 Brendel Informatik & SoftMaker Software GmbH.) also came with Serif's DrawPlus X2 and PagePlus X2.