Im using windows7. Purchased WD Passport 2TB two days before. I dont want regular backup of my PC just I need to work WD passport as USB Thumb Drive....that is to copy files from PC to Passport and use it from passport whenever needed. Is it is OK to just copy files from my PC to passport through windows file explorer. I dont want to use WD Smartware. But after I have copied the files to passport the disk space indicator does'nt show the space occupied by the file that I just copied and just showing only 1.81 TB free of 1.81 TB....Help me what is the problem..?