Micro SD card error I/O?

A few days ago I took the micro SD card out of my phone, and now when I put it back in the phone or the computer (indeed anywhere!) it tells me it cannot open the card because of an I/O erro, or that it needs to format the card, which subsequently fails.It is a SanDisk Micro SD HC 4GB card. If anyone has any help this would be much appreciated.

Hey t-man7,

That's a fairly large size in the world of SD Memory Cards.
I'm no phone expert and won't be of much help.
But it is worth mentioning that many devices require additional software/update to accommodate sizes over 2gb.
You may need to inquire with your phone manufacturer about that.

If it comes to you asking more questions here, it would of course help to know the brand and model of the hardware.

Best Regards