**Never** use the dangerous unverified import option, it is strictly for experts only. Especially, don't use it with any blockchain you download from the Internet, including the official site. It is only safe to use if a) you are importing a file that you exported locally, yourself *and* b) you are absolutely sure it was already fully and properly verified before exporting.
If your Monero software is on another drive you can use `DriveLetter:` for example if your Monero software was on your D drive then before using the cd command you would do `D:`
`monero-blockchain-import --input-file C:\YOUR\BLOCKCHAIN\FILE\PATH\HERE`