As you have already tried both the recovery tools from transcend and also the registry fix, it seems there is altogether a different problem with this pen drive. Try this pen drive in another computer (a friend's computer may be) and see if it works. If it works in a different computer the problem is with the Operating System.
Also, you can run an Anti-Virus scan on your computer to see if any virus is causing this problem.
If the issue is still not fixed, in your reply include the model number of your Transcend pen drive and I will see there is any specific issue/fix for this pen drive. Also, add the text of the exact error message that you get.
I have the same problem. I have tried solving it with diskpart, also with reged. I have scanned it, no virus is detected. There is also no switch on the body of the disk for write protection. It doesn't work on other computers, I have tried several. The model is 4GB Transcend JetFlash V90 Classic - Silver.
Try going into Start>right click "Computer">Choose "Manage"> Then in the window on left side choose "Disk Manager" and the look for the Flash drive. Then right click and choose Format or create new volume. I choose to creat a new volume and then formatted it as "Fat" (Not quick format but normal format). This worked for me. For some reason windows file manager won't do this but the Disk manager has no problems with doing this. Good luck.