Hi, is this a common problem?

I have so far changed 3 USB hubs. All have the same problem. The latest one is quite a good brand: Acrox. It has 4 USB2 ports and an external power supply.

The 4 ports are connected to:
1) an external DVD writer
2) External hardisk with enclosure
3) Printer
4) External USB Number pad

All except the number pad has own power supply.

Some of the problems I have encountered:

1) After STARTUP, NONE of the devices are detected by my computer (SOMETIMES only the 4 ports of the USB hub are detected as appear on Device Manager).

Sometimes, unplugging the USB hub then re-plug it to my computer will settle the problem. Sometimes, only re-plugging individual device to the USB hub will do.

2) When re-plugging the USB hub to the computer USB port doesn't work, re-plugging it to other USB port of the computer may work. I have 3 USB ports on my computer. However, using it on the new USB port will have the same problem as well.

3) On starting up my computer, just before the POST, I need to enter a password to access my computer. Usually I'll use my external number pad to enter my password bcoz my password are numbers only. Only sometimes, the number pad is usable. Sometimes re-plugging the number pad works.

Is it a power supply problem or it's the USB hub failure or the USB port of my computer?

What can I do. Thank you very much.aureusy...... After reading about all your other issues , I would say that you have some serious issues .......... and once identified ....it wouldnt surprise me if they all cleared up . .......... But you should really try to resolve one at a time ........ or consider a full format and reinstall.

dl65 Thanks dl65, I have thought of reformatting, but I find this troublesome. I need to bring my computer to my service centre to get an original installation becuase I have no Installation CD provided. Otherwise I will have to buy a new Windows software, which I can't afford to. In addition, I have a lot of important INFORMATION stored in my drive C. I need some time to to track my data.

Dilbert has suggested something. I hope he could help me to solve this problem. If after all, I can't, then I'll reformat my computer.

Thank you very much..