so do you have a wired connection to a router or other computer that has the direct via modem internet conection or do you have wireless connection to the host computer. If you have a wired connection through a router (ie:ethernet, or usb) then you should experience no problems. If you have a wireless connection to the host you may experience slower speeds at some times, but most of the time you will be unaffected by the distance.

P.s because i replied to this now more people who might have a better answer will reply most likely.

rs232 is for serial transmission, think like an old serial mouse or something. You're probably going to me more concerned with the Ethernet Standard, IEEE 802.3.

100baseTX Ethernet should not be longer than 100 meter (328 ft) from the concentrator (hub, switch, other port, etc). Any longer than that, and you might end up getting signal degradation.

...That's if you're talking about an Ethernet connection. Now, if you're talking about coaxial TV cable, which, because it's shielded, can travel a bit farther. The exact ranges, I don't know of, but I can tell you that it's significantly farther than Ethernet's Unshielded Twisted Pair.

Which one are we talking about? Is the Coax/CATV cable drop coming into your house, or is an Ethernet cable coming into your place?

When it's running through the CableTV/Coax, it's actually not Ethernet. It doesn't conform to the Ethernet standard until it comes out of the cable company's modem. At that point, the 100 M / 328 ft limit that Alc mentioned includes any patch cords and connecting cables at both ends of the run. This is a very stringent standard for good reason. In one of my former lives, I was the QC Manager for one of the largest data cabling companys in the state. Most of our work was government and military contracts. On more than one occasion we had to re engineer paths because they failed certification testing for going over distance even a few feet. But to answer your question, it will basically either work or it won't. There isn't a gentle drop off when you start to loose packets, the protocol starts to re-transmit dropped packets and if there is any significant number you get timeouts and your web pages just won't come up at all.
By the way, you can test this when you get it installed just by doing an extended ping to your default gateway with loaded packets. If you loose any on a regular basis then your link is trash. Just type ping [your default gateway address] -l 1500 -n 100 into your command or dos prompt and watch the result. I expect 100 % success rate on a decent link. The -l is a small L. This will send 100 packets loaded with 1500 bytes to the gateway and back.