I have an Acer Aspire 5738 laptop with 4GB DDR3 RAM with 320GB hard disk
and Intel Core2duo processor. I access the internet using my Samsung mobile using Samsung PC suite. I use Windows 7 Ultimate edition 32 bit. Whenever I remove the mobile cable from my laptop without disconnecting the internet connection, Windows 7 hangs and doesn't shut down. This problem does not occur if I use XP on the same system. Why does this happen, and how do I avoid this?

Also, Mozilla Firefox usually hangs while surfing the net I even repaired and reinstalled it but in vain. Please give me a solution. When I use Norton Ghost Backup,
it restarts my sytem in DOS mode and starts backing up. But during backup, the bar doesn't move beyond 0 per cent Even when I leave it for hours. Why?

(iv) I have 4 GB of RAM. So should i use 64 bit? What is he difference between 32 bit and 64 bit?