Can't copy anything to the drive..???!! (SanDisk Cruzer Blade USB Flash Drive - 32 GB - USB 2.0 )

a. FAT32 formatted drives can only hold files that are less than 4GB.  Reformat your drive as NTFS.

b. Do not copy your 4GB file to the SanDisk vault.  It will take forever.  Secure Access is an option not a requirement.  Copy your file to the drive using Windows Explorer.