Sometimes due to virus or sometimes due to internal problems,Network host process stops working and after that internet doesn’t work.The only thing you can do is to reboot the PC to restart the service.I have faced it several times and I was used to format the PC just because of that small problem.But there are some fixes to solve this problem.
Method # 1:
1>Click on start
2>’Run’ and open ‘Regedit’
3>Navigate to :
HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Services > Browser > Parameters
5>Find the Key Name: IsDomainMaster
6>set Data: False
7>Restart Your PC
Method # 2:
1>Open command prompt and type “netsh”
2>Type “winsock” and than type “reset”
3>Restart your PC
Method # 3:
Use this utility http://cexx.org/lspfix.htm
Method # 4:
Only for Windows XP Service Pack 2 users:
http://support.microsoft.com/kb/894391
http://support.microsoft.com/kb/958644
Method # 5:
1>Open “Regedit”
2>Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
3>Find the Key Name: EnableDCO and set Data:N
4>Restart PC
Source:http://en.kioskea.net/forum/affich-56033-win32-generic-host