Computer Infected with Win32/Netsky.C worms

I am facing the problem of Denial of service attack. Actually the thing is that I am having a setup of ten computers which are connected in network. Whenever I try to connect to other computers in network or try to transfer or copy files from other computers, either it does not allow me to do so, or in between the copying or transferring it just stops. And above all my all the computers are processing very slow. I have cleaned my temp folder and prefetch folder then also I am not getting the problem solved. One thing at last when I scanned the system, I am getting something like this
"Win32/Netsky.C worms" found on your system.

Denial of service attack normally make the computer services unavailable. I don’t think so you are having a Denial of Service Attack because it done by intended users to prevent an internet site to work efficiently. Normally they target web server with high profile, such as credit card gateways, banks.
Even if you think you are having Denial of service attack then do the following thing
1. Activate firewall on your network setting
2. Update you antivirus
3. Do not download any unknown attachments

Win32/Netsky.C is basically a mass mailing worm. It targets computer running windows XP, Windows7 or any other version of Microsoft windows . This worm sends itself to mails, which are on the infected computer. And the moment user download the attachment it gets activated.
Win32/Netsky.C creates the following registry key.
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
When you restarts your windows it starts duplicating.
If you are having network setup then it might be spreading by copying itself to network share folders. So just scan those folders and try to stop it.
Or
If you are good at handling registry clean the above mentioned registry key mentioned above.

Most of the antivirus software can prevent you from this threat of Win32/Netsky.C , but your antivirus software must be updated.
And enable your firewall setting using following options.
1. Go to control panel
2. Switch to category view.
3. Select the connection you want to help protect, and change settings of the selected connection.
4. Click advance and select preventing access to this computer from the internet
5. Ok and work is finished.