Help - Unable to access anything on R4?

When I turn it on from the DS, it sticks to the 'Loading...' screen, and freezes there. I plugged it into the computer, but when I try to open it from 'My Computer', it shows the icon of "Removable Disk L", but when I double click that it says 'Please insert a disk into Drive L'. I checked the USB, and the little light was on. Any ideas?

What type of MicroSD card do you have? Brand and Size?
What R4 are you using? A clone, original R4, etc?You probably don't have the firmware files on your MicroSD. Do you have any other method of connecting your MicroSD to your computer, a different adapter? Could be a bad MicroSD card, or a bad adapter. The adapter is usually the cheaper and easier one to try first.

It's a 2GB Kingston MicroSD chip, and I'm pretty sure it's the original R4, because I got it at the same time as my brother, and he updated his to the latest firmware using the R4 official site (forget what it's called right now.)Hmm, I did have another adapter (my brother's) but it stopped working for some reason (something that I previously posted on the forum), and that's why I switched adapters. If it was a bad MicroSD card, would the cause be random, or the 'age', or unknown? Because my brother's is working fine. Thanks