Chrome OS on old PC

Try this
http://www.neverware.com/landingpage#pricingcomparison

Here is a list of PCs that work. I assume other will also.

CloudReady installation guide (PDF)

I have not tried this. I did put Chrome OS on another old laptop but can't find that source. This may have been it. Just using Linux may be a better option.

But then why not just install Linux Mint and use the darn thing.