Have you checked Control Panel>>Hardware & Sound>>autoplay. Check Pictures. I have mine set to "Take No Action" You probably want "Open Folder to View Files Using Windows Explorer" selected, or possibly one of the other actions listed in the dropdown box.
I've tried the other SD card, both of which always worked in my computer before.
A few days ago I plugged my son's mobile phone in to one of the USB ports so think the problems have started due to this. I did get an error message come up (but can't remember what it said,something like the device was not recognised).
I've tried 2 system restores and gone back to the date before I used the mobile phone/usb device, it hasn't worked.
I have windows 7 - is there a way to do a repair without losing all my documents, photos etc. I do have the recovery discs if this is the only way to get the SD memory port to work again, but I know how lengthy this process can be.