Here is a way to do that without adding any software to your system ...

For each image, create a small text file -- the file name would be the same
as the image file name ... but ending in .TXT

Just type what ever contents information you want into the text file for
the corresponding image. 

Save the description text file into the same folder as the image.

Search using windows search and type what you're looking for into the
'Containing text:' field. 

If this sounds like a lot of work ... you're right, it is a lot of work -- OTOH,
if you bought software to help with the indexing, you would have the
same amount of effort to supply indexing information for each photo. 

This has the advantage of being free.  ... Except for your time, that is. 

HTH

--
Martin