Also running the cmd as administrator brings no solution:
C:\Users\Basti\Desktop>npm install i -g cordova
npm WARN engine npm@1.3.4: wanted: {"node":">=0.6","npm":"1"} (current: {"node":"0.10.38","npm":"2.7.4"})
npm WARN installMany normalize-package-data was bundled with npm@1.3.4, but bundled package wasn't found in unpacked tree
C:\Program Files (x86)\nodejs\cordova -> C:\Program Files (x86)\nodejs\node_modules\cordova\bin\cordova
i@0.3.2 C:\Program Files (x86)\nodejs\node_modules\i
cordova@4.3.0 C:\Program Files (x86)\nodejs\node_modules\cordova
Ôö£ÔöÇÔöÇ underscore@1.7.0
Ôö£ÔöÇÔöÇ q@1.0.1
Ôö£ÔöÇÔöÇ nopt@3.0.1 (abbrev@1.0.5)
ÔööÔöÇÔöÇ cordova-lib@4.3.0 (valid-identifier@0.0.1, osenv@0.1.0, properties-parser@0.2.3, bplist-parser@0.0.6, mime@1.2.11, semver@2.0.11, unorm@1.3.3, rc@0.5.2, shelljs@0.3.0, dep-graph@1.1.0, npmconf@0.1.16, through2@0.6.3, xcode@0.6.7, init-package-json@1.3.0, d8@0.4.4, elementtree@0.1.5, request@2.47.0, glob@4.0.6, tar@1.0.2, plist@1.1.0, cordova-js@3.8.0, npm@1.3.4)