can you use your existing phone line jacks and wire, then convert the jacks to lan to network computers or printers?
A LAN wire is wider, and used for VoIP and computer network access. A phone wire is what you use for your telephone, dial-up Internet access, and DSL Internet access.
No, you cannot use a phone line wire for LAN. The wires and jacks are different. Lan cables (cat5) have more wires inside than phone line cables which only have either 2 or 4 wires. If you need a LAN cable, you'll have to go out and buy one.
A phone jack, also called CAT3, usually has only two physical wires attached at the jack for a single line phone, 4 wires attached if a two line jack. It is meant to carry voice traffic from a standard telephone. The jack itself is called an RJ11 and usually has only four pins. A modern day LAN jack, also called CAT5, has eight wires physically connected to a wider jack called an RJ45. This is the standard wiring for Ethernet (even though only four of the wires are really used). When you are talking about the patch cord, the wire you use to connect a PC or phone to the wall, the Ethernet cord has eight wires and the phone cord has 4 wires inside the insulating jacket. The standard Ethernet used by PCs cannot use existing phone wiring for networking. However, there is special hardware you can buy to allow computers to communicate using standard phone wiring. But his has limited functionality, less range and slower speed than standard Ethernet. If you want to use this wiring for long term networking, I would invest in CAT5 wiring. For a few drops, it runs around $100 per jack. The other option is to buy a wireless router and use that to network your PCs.
There's really a big difference between a LAN and WAN connection. WAN connection can be easily interrupted by some interference compared to LAN connection. I would recommend that you instead check the speed that you are getting from your ISP instead of depending on the speed that you are getting out form you adapter connection statuses. If you really want to get a better WAN speed connection you might as well check your modem or router wireless setting cause ideally adapters are only there to receive a signal and if there is a problem with you getting a good speed still after making sure that your PC is working OK you might as well use another modem or router.
Yes the difference is that network cable (cat 5) supports 100mbs data transfer and has a range of 100 meters. Network cable is also shielded against R/F interference and uses a connector similar to a phone connector (RJ45) but is bigger. Phone cable is smaller in diameter and in most cases is not shielded it uses a (RJ11) connector. It may be possible to use the phone lines to connect your network but you would have to know how to terminate the ends of the cable. This takes a special tool and also the ability to do it. Its not that easy to do, Its easy if you have some one show you. I've been doing this for years, my advice would be to use network cable, do it right. wireless is the easy way to do it.