How to copy a file with spaces in its file name from one bucket to the other using AWS CLI (Dos)

Use double quotes. For example:

aws s3 cp "s3://source-bucket/My CV 2017.pdf" "s3://destination-bucket/My CV 2017.pdf"

Using double quotes can solve the problem when you have single file to upload.

For the bulk files, try uploading directory with recursive option

aws s3 mv ../directory-with-files/ s3://bucket-name/folder-to-upload/ --recursive