Interronator is paying Time Warner for 20mbps Internet service, but is only getting about .7 (note the decimal point).
[Email your tech questions to answer@pcworld.com or post them on the PCW Answer Line forum.]

Almost no one gets the Internet performance that their ISP advertises. Variables make Internet speeds impossible to predict, and the providers advertise the best possible theoretical speed.
But the difference between the advertised speed and the real one should be reasonably close. If you’re regularly getting less than 70 percent of what you were promised, and the price you’re paying isn’t amazingly low, you’ve got a serious bottleneck.
(If you don’t know how to test your Internet connection, visit www.speedtest.net and click the big BEGIN TEST button.)
That bottleneck may be on the ISP’s end, but it may also be on yours. A few simple diagnostics may tell you who to blame:
First, try another computer. If you’re getting acceptable performance on one computer but not on another, you can’t blame the ISP.
Next, consider and test the way your computer connects to the router. If you’re using WiFi, try Ethernet. If you’re using Ethernet, try another Ethernet port on the router, or try another cable.
Try replacing some other cables, such as the one connecting the modem to the router. If that doesn’t work, try the one connecting the modem to the wall (and I don’t mean the AC power).
Try updating the firmware for the router and, if that doesn’t work, the modem. Check the manufacturers’ Web sites for firmware updates.
If none of these tests solve the problem, try taking the router out of the equation by plugging the PC directly into the modem. You may need to change some operating system settings to make this work. Check with your ISP about them. If this solves the problem, you need a new router.
Consider replacing your modem. Your ISP may provide you one, or you may have to buy one on your own. If you go the later route, buy from a store with a good return policy, and keep all of the packing material.
If none of these solve the problem, you’re now allowed to blame your ISP. If they can’t or won’t fix it, consider taking your business elsewhere.
My thanks to Smax013 for making the firmware suggestion in the original forum discussion.