Here I assume that you are using WAMP 2.5, and not 2.6 as you wrote in the message. Which is accessible at https://sourceforge.net/projects/wampserver/files/WampServer 2/Wampserver 2.5/. PHP extension 2.1.0 located at http://sdk-snapshots.couchbase.com/php/php_couchbase-2.1.0-5.5-zts-vc11-x64.zip. Unpacked extension into C:\wamp\bin\php\php5.5.12\ext\php_couchbase.dll and libcouchbase.dll somewhere in the PATH (In my case into C:\wamp\bin\php\php5.5.12\libcouchbase.dll and C:\wamp\bin\apache\apache2.4.9\bin\libcouchbase.dll).
Couple things here:
- wamp does not ship
php5.dll(NTS version), but ratherphp5ts.dll(ZTS version), so you used incorrect archive - when extension is loading, it looks up for
libcouchbase.dllin thePATHor in current directory of the process so this DLL should be accessible there (for some reason OS keep removinglibcouchbase.dllfromC:\windows\system32. - when registering extension for CLI mode, use
C:\wamp\bin\php\php5.5.12\php.ini, and for apache, useC:\wamp\bin\apache\apache2.4.9\bin\php.ini. The real INI file location you can always findout during runtime:
CLI:
C:\wamp\bin\php\php5.5.12>php --ini
Configuration File (php.ini) Path: C:\Windows
Loaded Configuration File: C:\wamp\bin\php\php5.5.12\php.ini
Scan for additional .ini files in: (none)
Additional .ini files parsed: (none)
Apache httpd:

So if you did everything like I’ve described above, you should be able to successfully verify installation:
CLI:
C:\wamp\bin\php\php5.5.12>php.exe -i | find "couchbase"
couchbase
Apache
