How to solve blank card issue: (i have this issue too)
If Android says card is blank or unsupported, i would try to put SD/HC card into card reader and insert reader into USB port of your PC. Then it should connect as a new drive. Copy all data from SD/HC card to your computer. Then try to add card into mobile again. If still not working (i think it wont work), then "Format" this SDHC card from Windows. From windows Vista i have it when i right click on the SD/HC drive. FAT32, Quick format. Then copy data from computer back to card. Insert into Android device, it should work.
In case not android and not computer recognise drive, i would try to add card reader into different USB port or different computer. If computer shows like no drive is inserted, drive is probably damaged, and i was not able to format it even using third party formating tools and not chkdsk windows tool. The solution is to ask specialised firm to help you recover data. It can cost like 100usd or more. Another thing is to forgot about data and buy new SD/HC card for your mobile.
If Android says card is blank or unsupported, i would try to put SD/HC card into card reader and insert reader into USB port of your PC. Then it should connect as a new drive. Copy all data from SD/HC card to your computer. Then try to add card into mobile again. If still not working (i think it wont work), then "Format" this SDHC card from Windows. From windows Vista i have it when i right click on the SD/HC drive. FAT32, Quick format. Then copy data from computer back to card. Insert into Android device, it should work.
In case not android and not computer recognise drive, i would try to add card reader into different USB port or different computer. If computer shows like no drive is inserted, drive is probably damaged, and i was not able to format it even using third party formating tools and not chkdsk windows tool. The solution is to ask specialised firm to help you recover data. It can cost like 100usd or more. Another thing is to forgot about data and buy new SD/HC card for your mobile.