Help Can't browse my SD

[JAmPP]

I connect my phone (Xperia Play) to the PC (Win7). I can see files and folders in SD card, in windows explorer but I can't open any of them. I tried to disable ReadOnly property, but it shows:
(Unable to access X:
Location unavailable).

How can I fix it without reset to factory settings?

Thanks in advance.
--
JAmPP

 

[Sam-SonyXperia]

If you try to right click on the files and open properties, does it show the size of file and if so does the size appear to be accurate?

 

[Cl8rs]

Is the back cover on your phone completely snapped on?

 

[JAmPP]

Yes (both of them). I just figured it out. I'm trying to browse it (the SD, of course) from the job's PC, they have just blocked USB ports and CD writers (for "security reasons").
I tried to plug it and browse the SD in 3 different PC. It worked fine the three times.
I switched as Media Transfer Mode, and I could do everything "as usual".

Thanks for your timely answers, @Sam-SEanswers and @Cl8rs.

 

[Sam-SonyXperia]

No problem, glad that is sorted for you