Invalid Product Key?

"I often tell my people that I do not know which areas I belong to, and I just reckon myself to be a trouble shooter." - Ji-Rong Wen, Microsoft Research

It would scare anyone for a minute (or more) when they find that expensive software they have purchased and started to install, asks for a product or license key number and then spews out a warning "Invalid Product Key" after they type out the typically alpha-numeric set of cryptic characters.

This often happens because the font used for printing the keys is sometimes misleading. Sometimes "B" is mistaken for "8" and "O" (capital "o") with "0" (zero). So the next time you come across this warning, verify if misinterpretation of the character due to the font type is not the issue before letting panic strike. If this happens for a Microsoft product, check these troubleshooting tips & try the phone activation method.

The classic book on Programming guidelines "Code Complete" has an entire chapter on naming Variables in programs. It suggests avoiding names containing hard-to-read characters. These include pairs that are hard to distinguish like (1 and l), (1 and I), (. and ,), (0 and O), (2 and Z), (; and :), (S and 5), and (G and 6)