Hi, I recently upgraded my computer from windows xp to windows 7 64 bit. Everything works fine except today when I plugged in my USB stick. It came up with device not recognised and I couldn't access it. I've tried in all USB ports, with no luck. Tried using another device int he ports, which worked fine. Tried 2 other USB sticks, neither of which work, same results. Tried formatting the stick and trying again, no luck. I've had windows 7 on my laptop for a while now (it came with it), and thats been fine. The memory sticks all work on that fine in any port. I really don't know what more to do. Hope somebody can help.