You're absolutely right. It's not needed by the general public. Marketing it as such might be holding it back.
I googled it. The top hit was CNET's "download.com" where the typical package might be bundled with crapware or worse. Allowing them to provide it taints your product's perception.
I went to the website. The positive connotations of Windows XP are gone with the passing of Vista. The screenshots look dated. Windows built in search catalogs MSWord documents. It's not a defining feature.
What are the defining features? Things like what you listed in response to my question. Things that can remove a world of hurt, not the 90% that's redundant or a visual interface from 2001.
I went to the pricing. $10 is too high for anyone who wants free and too low for anyone who correlates price with quality.
My two cents:
Raise the price.
Get rid of the trial version.
Target it at business.
Emphasize the PDF search.
Target it at IT.
Emphasize the Network search.
Price it as free or expensive.
Ten bucks for shareware is dead.
Good luck.