Here are the steps that I followed when I encountered issue with external USB Hard drive. The external hard drive is mounted as “D:” when connected to the computer. But I received the following error while accessing the files

D:Drive not accessible. The parameter is incorrect.

Here are the steps I followed in order to resolve this issue:

Open command prompt by right clicking “run as administrator”. Note the external drive in question is “D:”.

C:WINDOWSsystem32>chkdsk /F /R /X D:

This process will go through the following stages:

Stage 1: Examining basic file system structure ...
Stage 2: Examining file name linkage ...
Stage 3: Examining security descriptors ...
Stage 4: Looking for bad clusters in user file data ...
Stage 5: Looking for bad, free clusters ...

Note: this process took approx. 4 hours to run against 500GB External Hard drive.