ELECTRON_WIN_VERSION_NUMBER=1.7.0
ELECTRON_WIN_BUILD_NUMBER=11
ELECTRON_MAC_VERSION_NUMBER=1.7.0
ELECTRON_MAC_BUILD_NUMBER=11

For /F "tokens=1* delims==" %%A IN ("build.properties") DO (
    IF "%%A"=="ELECTRON_WIN_VERSION_NUMBER" set ELECTRON_WIN_VERSION_NUMBER=%%B
    IF "%%A"=="ELECTRON_WIN_BUILD_NUMBER" set ELECTRON_WIN_BUILD_NUMBER=%%B
)

echo "%ELECTRON_WIN_VERSION_NUMBER%"
echo "%ELECTRON_WIN_BUILD_NUMBER%"

""
""

"1.7.0"
"11"