NPM Install fails on EISDIR illegal operation on a directory

[GrandmaTi]

Hi there,
I tried to install npm packages in an imported project (https://github.com/coryhouse/react-slingshot) as shown in Get started (as well as with npm run setup and npm install).
Every time the installer stops by the step node@8.9.4 preinstall: 'node installArcSpecificPackage'.

From the console:
fs.js:119 throw err;
Error: EISDIR: illegal operation on a directory, link "...react-slinshot\node_modules\node\node_modules\node-win-x64\bin\node.exe" -> "...react-slinshot\node_modules\node\bin\node.exe"
at Object.linkSync (fs.js:907:3)....

From the log-file:
100 warn ajv-keywords@3.2.0 requires a peer of ajv@^6.0.0 but none is installed. You must install peer dependencies yourself.
101 warn babel-loader@7.1.1 requires a peer of webpack@2 || 3 but none is installed. You must install peer dependencies yourself.
102 warn react-router-redux@5.0.0-alpha.6 requires a peer of react@^15 but none is installed. You must install peer dependencies yourself.
103 verbose stack Error: node@8.9.4 preinstall: node installArchSpecificPackage
103 verbose stack Exit status 1
103 verbose stack at EventEmitter. (C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\index.js:304:16)
103 verbose stack at EventEmitter.emit (events.js:182:13)
103 verbose stack at ChildProcess. (C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\lib\spawn.js:55:14)
103 verbose stack at ChildProcess.emit (events.js:182:13)
103 verbose stack at maybeClose (internal/child_process.js:961:16)
103 verbose stack at Process.ChildProcess._handle.onexit (internal/child_process.js:248:5)
104 verbose pkgid node@8.9.4
105 verbose cwd U:\react-slingshot
106 verbose Windows_NT 10.0.17134
107 verbose argv "C:\Program Files\nodejs\node.exe" "C:\Program Files\nodejs\node_modules\npm\bin\npm-cli.js" "install"
108 verbose node v10.5.0
109 verbose npm v6.1.0
110 error code ELIFECYCLE
111 error errno 1
112 error node@8.9.4 preinstall: node installArchSpecificPackage
112 error Exit status 1
113 error Failed at the node@8.9.4 preinstall script.
113 error This is probably not a problem with npm. There is likely additional logging output above.
114 verbose exit [ 1, true ]

The same project installation works fine on different PCs, only my system has problems with installing all packages.
Is there any idea?

[Edit] I found out, that the project runs without any errors on my C-drive...have absolutely no clue, why not on an other driver..(also in root)