HELP: Device I/O error

I am completely baffled.

When I try to access on folder on my G drive (internal)...I get the I/O error and the folder won't open. Every other folder on the G drive opens fine.

Of course, all of my music is in the folder that won't open.

When I run a virus scan....I can see all of the files in the folder...and no errors come up.

What can I do?

I really don't know a lot about cpu....and can really use someone's help I really don't want to lose ALL of my music.

Thanks

Nit

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 8.1 Pro with Media Center, 64 bit
Processor: Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz, Intel64 Family 6 Model 58 Stepping 9
Processor Count: 8
RAM: 16334 Mb
Graphics Card: NVIDIA GeForce GTX 670, -2048 Mb
Hard Drives: C: Total - 1907626 MB, Free - 1448603 MB; E: Total - 305234 MB, Free - 305051 MB; F: Total - 305234 MB, Free - 305051 MB; G: Total - 953857 MB, Free - 600414 MB;
Motherboard: ASUSTeK COMPUTER INC., SABERTOOTH Z77
Antivirus: Windows Defender, Disabled