1) Goto Run (Start»Run OR Win Key + R)
2) Type cmd and Ok
3) Change the drive location to the drive which is not opening (Drive letter followed by colon e.g. E:)
4) Type following command confirm if autorun.inf file is present there
5) Type: attrib -S -H -R autorun.inf
6) Type: del autorun.inf
7) Now simply go and rename the original drive label in My Computer.
If this work for the first drive then try same steps for your second drive.