As the Anti-virus software did a viral quarantine and deletion.
After deletion, the USB thumbdrive is unable to be “left-double-clicked”. When double-clicked, Windows will launch a windows saying some files cannot be found. It was that my Autorun.inf file (the file that is used to Autorun specified programs) has commands to launch certain programs on the thumbdrive. Apparently, the virus overwrites the old Autorun.inf to an infected one which launches the virus everytime the thumbdrive is placed into a PC. Thus, this is the solution that you should do if you are facing the same problem.
Do a virus scan on your thumbdrive. Next, backup your data (just to be safe) to a hard disk.
Later change your Autorun.inf by the following steps:
1. Go to tools -> folder options -> view tab: check show hidden files and folders and click OK.
2. Go to My Computer -> Right-click your thumbdrive -> explore.
3. In your Windows explorer, right click on the file on your thumbdrive with name "Autorun.inf" -> Choose "open with" -> select "notepad.exe "
4. Delete all the contents inside the file, and replace the contents with:
+++++++++++++++++++++++++++++++++++++++++++++
[autorun]
shell=Open
+++++++++++++++++++++++++++++++++++++++++++++
