Unable to copy files greater than 100 MB to USB pen drive?

I have dell Inspiron 530. For few weeks I have been having trouble copying files greater than 100 MB or more to my USB 8GB pen drive or any other pen drive. It works fine for small files like docs and pictures but when I try to copy a movie the pen drive icon on my computer becomes disabled and the copying get stuck. I also have a external USB hard disk and that has no issues with any port it works perfectly fine only issues is with copying files to pendrive. I have formatted my computer twice to check if any issue with viruses but still same problem. My pen drive works well on other computers, but no pen drive works for copying large files on my computer. Also the external hard disk works as well. I dont understand what the real problem is. Please help me out. Any suggestions would be helpful. Also I am unable to format it as NTFS I tried but its taking a long time and no response