This probably depends upon how you are logged onto the server,

but even if you have Windows Explorer set to show hidden files and system files,

you still might not see these config files on any search,

UNTIL

you have, at least ONCE, navigated to those folders, in Windows Explorer.

WHY I say that:

I had tried repeatedly to find "RSReportserver.config", and had never seen it show up on *any* search -- not using Windows Explorer, nor SuperFinder XT, etc. --

Then today, I used Windows Explorer to navigate, and even though I was logged on as a domain admin, as I double-clicked "Reporting Services", I got the familiar prompt:

"You don't currently have permission to access this folder.

Click Continue to permanently get access to this folder."

I clicked Continue...

... and saw the "RSReportserver.config" file!...

... and after that, very interestingly, the "RSReportserver.config" file (and others in "*.config") STARTED SHOWING UP ON SEARCHES!

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In our case, it was in folder:

C:\Program Files\Microsoft SQL Server\MSRS10_50.MSSQLSERVERBO\Reporting Services\ReportServer

But I've seen variations of that location, online (while wasting say too much time, on internet searches and windows explorer searches, trying to find it!)... ... variations like:

<drive:>\Program Files\Microsoft SQL Server\MSRS11.MSSQLSERVER\Reporting Services\ReportServer

or, in BOL (which did not match my reality):

\Program Files\Microsoft SQL Server\MSSQL.n\Reporting Services\ReportServer