ahh yes, if it's for non-commercial use, I've always received permission from BelArc to use their BelArc Advisor software. This will give you the product activation codes of most (perhaps all) of your software if you can't locate them. quoted from their FAQ:
BelArc:We do offer some charitable organizations a license to use the Belarc Advisor at no cost, under certain conditions. Please send us information about your charity, a url and the number of PCs and servers. Email: info@belarc.com
So email them and ask if you can use it at your non-profit.