If your PC is running low on space and its performance is gradually decreasing then it is time to run a disk cleaner. A good option was CCleaner but it is a paid product now. CCleaner best alternative is BleachBit.
Since IDM (Internet Download Manager) is not free and the cracks available are malicious and tagged by almost antivirus as harmful to your computer. EagleGet is the best free alternative to IDM.
/bin/bash^M: bad interpreter: No such file or directory is a error thrown by Linux and Mac OSX operating systems when a Shell script is executed which was created in Windows environment.
"Windows was unable to complete the format" is a error that may occur to both SD cards and USB devices. This can be due to many reason like bad sectors in the disk or may be result of a malicious activity by a program like virus or a worm. It can also be caused if the SD card or a USB is damage.