Problem with network connection

Hello,

I got a problem over here....i installed a program from the hardware,& it says need 2 reboot, & i did it.After rebooting,the com locked by itself.I tried locking in a few times, but still cant unlocked..After few days, i found the com is reformatted by someone in our home...but the problem is that i cant go in e web broswer..it says e broadband modem is not connected to the com..i tried again & again...but still cant go into e web broswer...can anyone tell me what the problem??? thank alot