Last year, I highly recommended Copernic Desktop Search [copernicdesktopsearch, copernic2] over all the other desktop search apps that I tested. I was using CDS version 1.7. CDS was faster, easier to use, and had a lower system impact than the rest.
Unfortunately, Copernic has upgraded CDS to "Version 2," and it's a poor step backwards. It's still free, and I hate to complain about free software, but…
CDS 2 is slower than 1.7, adds unneeded features, and above all, has some horrible user interface quirks. Specifically, the worst feature is their new "Search web" link on the desktop search box. If you mouse over this link, which you must do in order to choose a search category, the link becomes permanently active, causing all desktop searches to become web searches instead. You can't deselect this link! Or even disable it! This, of course, makes CDS 2.0 effectively useless for desktop search. Sure, you could theoretically press Win-C to open the CDS desktop app and enter your search there, but unlike CDS 1.7, Win-C no longer give the app input focus. This means that you need to use the mouse to click to enter your search term. Ridiculous!
Last year, Copernic searched the net for published recommendations, found mine, and posted an excerpt on their web site. I would like to now publicly recommend that users avoid CDS 2.0, and request Copernic to remove my recommendation.
That said, I still use and recommend CDS version 1.7. If you scour the net, you'll find CDS 1.7 on oldversion.com. Just don't upgrade when prompted. 
What you say about CDS 2.0 is totally correct. I'm really upset that they have screwed it up by supposedly upgrading to 2.0. I made the mistake of upgrading and it was so hard finding the older version 1.6/1.7 versions - I now have it. I guess sometimes newer isnt better.
I too prefer Copernic 1.7 to 2.0. My reasons are the same as those already stated, but an additional gripe for me is that I like to dock the deskbar along the top edge of the screen. This works fine in 1.7 but won't work in 2.0.
An easy way to revert to version 1.7 build 977 is to download Mamma Desktop Search instead. The URL is http://www.mamma.com/desktopsearch/.
It seems that Mamma.com bought Copernic. Interesting that they still offer the Mamma-branded version as version 1.7 instead of version 2.
The only difference from the old Copernic 1.7 seems to be the branding and the default URLs for web search.
As a bonus I find the Mamma web search can be quite useful.
Nice, thanks for the tip about Mamma. It is indeed Copernic 1.7, and it works without the 2.0 upgrade nag. I hope it stays this way. Great find!
Totally agree with the previous postings. 2.x is a downgrade from v1.7. It's as if they let their competitors' offerings dictate the upgrade.
