The Windows Subsystem for Linux makes your full Windows system drive available so you can work with the same files in both environments. However, the Bash environment doesn’t just dump you in your C:\ drive. Instead, it places you in your UNIX account’s home directory within the Linux environment’s file system.
Your Windows system drive and other connected drives are exposed in the /mnt/ directory there, where other drives are traditionally made available in the Linux directory structure. Specifically, you’ll find the C: drive at the following location in the Bash environment:
/mnt/c
To change to this directory with the cd command, just type:
cd /mnt/c
If you have a D: drive, you’ll find it located at /mnt/d, and so on.