i have 2 pc's and 1 hub 100mhz(micronet sp516),both pc's have realtek8139 card's, i have the latest divers for lan card's but still not work both pc's connected with 1 hub 10 mhz(noname) please help i'm going mad!!!

Why not use a crossover cable? Then you can take the hub right out of the equation!

A couple things to check..Are the IP address on the same sub-net (192.168.0.1, 192.168.0.2 so on)and are they in the same workgroup. Check by right clicking net neighborhood > properties > and check in the Identification Tab. If you can't see both PC on the in net neighborhood it's a good chance you TCP/IP config is incorrect or you're not in the same work group. Let us know how it goes.

you say your nic cards are 100mhz? and your hub is 10mhz?

If your hub is 100 mbit only and not 10/100, then it cannot talk to the cards at the slower rate. Depending on your needs, you have several options given your current situation. You can replace both your cards with 100 mbit or 10/100 models. You can replace your hub with a 10 model for about 30 to 40 dollars if you check out pricewatch.com. Unless you do a lot of large tranfers from machine to machine, just replace the hub; you don't need the 100 mbits for mplayer games or printer sharing. The 10 mbit capable hub has the added benefit of being the correct speed for sharing a cable modem or DSL line with both computers. If you want the 100 mbit speed for computer to computer transfers and to share a cable line you will need to get a 10/100 autosensing hub and the two FastEthernet cards as well. good luck

I'd agree that if you're only going to be connecting 2 machines then it'd be cheaper just to get a crossover cable and connect the 2 cards direct.

I understand you are ok as far as the nic and the hub, the RTL 8139 nics are 10/100 while hub is 100mb/s (you wrote 100mhz). Check if the nics are setup at 100mb/s . If autosensing that must be OK too.(there is a DOS utility coming with the NIC on diskette to setup ???setup.exe). Check if proper drivers for your ver of windows have been loaded (the ones coming on the diskette with NIC should be OK). Check if you have specified same workgroup for both machines, same subnet mask (255.255.255.0), progressive IP addresses starting from 192.168.0.1 for the host. Ping each machine from the other to see if your utp cable & hub Ok or not. Hub can be tested by temp swapping with a known good one, likewise for the utp cable. Cannot think of anything else. What protocols have you installed? Are they bound with the nics? Have a self test done on the nics to check their configuration and performance etc..