Windows 8's desktop search seems not to index PDFs. Is this by design or have I misconfigured something?
Windows 8 should be able to index PDFs out of the box. Just press Win+W / type "index" / Indexing Options / Advanced / File Types tab, select PDF and ensure that Index Properties and File Contents is selected:
Also, as per this Adobe forum thread, seems like installing Acrobat XI can actually break Win8's PDF indexing ability. Considering the fact that Adobe's iFilter/preview handler+thumbnailing feature has been broken for more than 3 years now, this comes as no great surprise to me. Adobe has responded with an official workaround to restore the native Windows 8 PDF iFilter functionality.
This issue also can happen on W7 - the answer my also help you http://answers.microsoft.com/en-us/windows/forum/windows_7-files/i-need-to-index-pdf-files-in-my-laptop-running/ef5fa7c3-bb64-4f3e-9607-3e01349dccca
So, for Windows 7:
Go to Indexing > Advanced > File Types, and remove the check for PDF. Press OK > Press Close.
Then uninstall any Ifilters that you have relating to searching PDF Files.
Re-install Acrobat if lower than version 9.3
This worked for me in Windows 8.1 with MS Reader, Adobe Reader and Foxit Reader installed:
Change registry key per Adobe's instructions.
Restart (may not be needed).
Now Windows Explorer shows PDF content in the search results.