Wow, terrible download speed! 😟
Remove all power and cables from your modem and Router for 5 Minutes.
Power up Modem, wait 2 minutes.
Power up Router, wait 2 minutes.
Try the Speed Test again.
Might even be your ISP, has it always been this way?
At this point I think you should get Applejack...
http://www.versiontracker.com/dyn/moreinfo/macosx/19596
After installing, reboot holding down CMD+s, then when the DOS like prompt shows, type in...
applejack AUTO
Then let it do all 5 of it's things.
At least it'll eliminate some questions if it doesn't fix it.
The 5 things it does are...
Correct any Disk problems.
Repair Permissions.
Clear out Cache Files.
Repair/check several plist files.
Dump the VM files for a fresh start.
First reboot will be slower, sometimes 2 or 3 restarts will be required for full benefit... my guess is files relying upon other files relying upon other files! 🙂
Disconnect the USB cable from any UPS so the system doesn't shut down in the middle of the process.
How much free space on your HD?