You want to copy data from a USB stick which seems partly corrupted, e.g. during the copying process Windows suddenly hangs.
If Windows chkdsk does not help, try HDD Raw Copy Tool. Unlike Win32DiskImager, this tool skips bad sectors and CRC errors and nearly always finishes the image.
Open the created image file with 7-Zip and try to extract your data now.
Note: This might only work with files which allow the loss of some bytes, like image or video data.