BleepingComputer.com: Network Cable Unplugged Baloon Pops Up On All Computers

hello I am venkat ,I came to know this through google I myself is a computer service engineer .
I had a problem Ii hope you will solve it.
The problem is a netwok cable unplugged message come on all computers connected through lan.
Operating system on all is windows xp sp2.
Hp laser1018 printer as a printer sharecd for all.
A 8 port swich i am using.
When the message comes of network cable unplugged ,and it comes to normal after 1 minute this is happening continously.
I changed my switch and checked with hub then internet is slow ,though these messaages are keep coming what do i do.
please provide me any solution.
This is my first post please forgive me if any mistakes.

I can only think, that the problem lies in your switch, because all computers experience the same problem. When this occurs, did you check your switch and confirm that it still powered ON? If you already replaced the switch, please check the power outlet where it is plugged-in. It could be loose power plug, or maybe the AC power outlet is the problem. Try to transfer to another AC outlet or change your Power Strip(if you're using one) and see if that solve your problem. It's better if you have UPS that handles power of your Switch, modem and router.

sir thanks for your reply
I changed my switch and tested with hub as of internet is very slow because of slow data transfer of hub and these netwolrk cable unplugged coming and going again .I changed surgeprotector it's still the same problem only thing I left is changing that another power outlet .