How do I change letter designation of an External Drive?

[Solnyshko]

Driving me round the bend - my external drive has for no apparent reason changed from J:/ drive to G:/

I need it to revert as my Lightroom catalogue is unable to locate my photo library. Urgently have to batch process a load of RAW files for work...

Any help greatly appreciated!

(Running Win7)

 

[marc2003]

start>type in diskmgmt.msc

then right click the partition>change drive letters and paths.

 

[Solnyshko]

Genius. Thank you!