1. windows xp 32 bit
2. i dont realy get that question but i think you mean amount i have six on the back of my pc
3. 2 ports
4. 10 ports tecknet hub
5. input: 100-240v
1.2a
12v
4000ma
6. i just put all of them in the hub
7. hp compaq dc7600
Ok, so there's actually a few things.
1.) This should be fine for what your doing.
2.) Ok, you can most likely put 3 ASICS on the back of your PC but I wouldn't recommend doing that, good way to fry a motherboard should the current be more than what it can handle.
3.) The two ports can host ONE miner. That is all.
4,5,6) This hub isn't going to be powerful enough to run all of these. At most you could put 7. Yes, the math (2.5W = 5V * .5 A) means that you *could* put 8 ASICS in this one hub (4000ma = 4A/.5A = 8 ASICS possible) but really you can't. The ASICS user power to both mine AND send/receive data. The draw will be too high and the hub might not be able to compensate even if it pulls more from the computer.
7.) it's an older model which confirms that the USB ports might not be up to snuff. Manufacturers like to cut corners with power and the best place (was) to under power the USB ports. Though they can run USB 2.0 devices most devices require less than the maximum power to run.
As a test, try plugging in 7 devices into the hub, then get mining running. Once it's stabilized (wait like 5 minutes) try to add one more ASIC and WAIT until the light stops flashing on it and turns a solid green. If your mining software detects it and starts work, great try adding one more until it stops working. If it stays green see below:
If your using bfgminer you must get the com port that the new device is running on (open device manager while adding it) and press M then + (manage devices, add new device) then type in the corresponding COM port (e.g. //com8). If it says No New Device (or no device found) then the device can't initialize and however many you've added to the HUB is the max that HUB can support.
If your using CGminer (with ASIC support) it should automatically detect the new device and just start working. Keep trying to add (once the 7 are stable) until NO additional devices are recognized. This is the max that the HUB can support.
BTW. For all of you who say it's a driver problem your wrong. His computer "sees" 7 of them, which means the drivers are working correctly. 3 (assuming OP bought 10 for a 10 port hub) don't have enough power to run. He needs to either get another HUB and run 7 in each OR try using the ports directly on his motherboard (not recommended). It isn't a driver issue here it's simply that the ASICS aren't getting enough power to run.
On a side note, try stopping the mining software and plugging them all in, they should all light up (solid green) because with NO work they only require a very small amount of power.
Also as otsaku said, try plugging each device in (alone) to the hub and see if it can start mining if it doesn't it might be bad (DOA).
Please let me know if this helps you.