Not able to open files on a usb for crafting

I have used Adobe for many years now but I cannot get the system to open any files on the usb's I just get a message to say the Reader cannot open file because it is either damaged or not a supported file, I am getting so frustrated. I have now 6 times taken Adobe off my computer and reinstalled it but nothing helps, can anyone please help me as I use the files dayly?  xx