I've been searching for a way to access a USB drive connected to the USB port on the router, without installing the Shareport software. Maybe this info was posted before, but I could not find it on these forums. In case anyone else wants to know, here's how to do it.
How to map a USB drive attached to DIR827 from Windows Explorer:
In Windows Explorer, go to TOOLS > MAP NETWORK DRIVE
Choose a letter for the drive (use the last ones, V to Z. Avoid mapping to the next available letter, especially if you choose 'Reconnect at Log-on', as this could cause conflicts when you add and remove other removable drives.)
For Folder, enter this:
\\192.168.0.1\Storage(A0)
or, if that does not work:
\\192.168.0.1\Storage(B0)
I assume that these names are reserved in the router for the USB port and for the SD card slot. However, they seem to be assigned randomly. In my case, initially the USB drive was B0. After a reboot of the router, it was A0. Each time it changes, you'll have to re-map the drive as described here. That sucks.
Click Finish, and you're done. The new drive should now appear in Windows Explorer as a Network drive. You can use it as any other drive on your PC. Although transfer rates will not be great.
Because the name seems to change after each router reboot between Storage(A0) and Storage(B0), I would avoid enabling the 'Reconnect at Log-on' option. Rather, map it manually as described here only when you need to transfer something to/from the drive.
If you simply want to see the content of the drive, or transfer a file to your PC, you can just enter
\\192.168.0.1\Storage(A0) or \\192.168.0.1\Storage(B0) in your web browser window.
You can play movies, mp3s, view pics, and download files from the drive.