sorry being the thousandth asking this, but none of the solutions helped me. I have a fresh postgres 9.4 x86 install and build the qt psgl plugin by myself. Then I copied qsqlpsqld.dll to myapppath/debug/sqldrivers and set Path to my postgres bin directory.

Unfortunately I only get the well known "PSQL driver not loaded"

Dependency Walker (seem to be missing, but for every dll I checked):
api-ms-win...
dcomp.dll
gpsvc.dll
ieshims.dll

Debug output from shell:

QFactoryLoader::QFactoryLoader() checking directory path "C:/PROGRA~4/Qt/5.3/mingw482_32/plugins/sqldrivers" ...
QFactoryLoader::QFactoryLoader() checking directory path "myapppath/debug/sqldrivers" ...
QFactoryLoader::QFactoryLoader() looking at "myapppath/debug/sqldrivers/libqsqlpsqld.a"
"Plugin verification data mismatch in 'myapppath/debug/sqldrivers/libqsqlpsqld.a'"
not a plugin
QFactoryLoader::QFactoryLoader() looking at "myapppath/debug/sqldrivers/qsqlpsqld.dll"
Found metadata in lib myapppath/debug/sqldrivers/qsqlpsqld.dll, metadata=
{
"IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
"MetaData": {
"Keys": [
"QPSQL7",
"QPSQL"
]
},
"className": "QPSQLDriverPlugin",
"debug": true,
"version": 328450
}

Got keys from plugin meta data ("QPSQL7", "QPSQL")
QSqlDatabase: PSQL driver not loaded
QSqlDatabase: available drivers: QPSQL QPSQL7

Any ideas are welcome ;-)