Error: Cannot find specified path for mongodb data/db/testReplSet-0 when replicaSet.startSet()

Trying to get the test setup locally for mongodb replication.
Steps I followed are: $ mongo --nodb

replicaSet = new ReplSetTest({"nodes" : 3}) // starts three mongod processes replicaSet.startSet()

The third step is throwing errors. I already have a existing mongo db server running at port 27017 and data of that is stored at different folder in as specified in mongod.cfg

Im trying to create a test replica set on mongod instances on different ports . The steps shown in below image show that 3 ports where selected for replication. Also I have made sure that we have a directory /data/db in {mongodbinstallation folder}\bin\ still i get the error for path not found.

Error shown in image is here

Thanks for the help.