FOR GENERIC HOST PROBLEM IN XP MACHINE.........

To resolve this problem, follow these steps:
1. Click Start, click Run, and then type net stop wuauserv.

2. On the desktop, double-click My Computer, and then delete the drive:\WuTemp folder.

3. Delete the drive:\Windows\System32\Catroot2 folder.

4. Open the drive:\Windows folder, and then rename the Software Distribution folder as Software Distribution OLD.

5. Open the drive:\Windows\system32 folder, and then follow these steps:

a. Rename the Wuweb.dll file as Wuweb.dll.old.
b. Rename the Wuapi.dll file as Wuapi.dll.old.
c. Rename the Wuauclt.exe file as Wuauclt.exe.old.
d. Rename the Wuaucpl.cpl file as Wuaucpl.cpl.old.
e. Rename the Wuaueng1.dll file as Wuaueng1.dll.old.
f. Rename the Wuaueng.dll file as Wuaueng.dll.old.
g. Rename the Wuauserv.dll file as Wuauserv.dll.old.
h. Rename the Wucltui.dll file as Wucltui.dll.old.
i. Rename the Wups2.dll file as Wups2.dll.old.
j. Rename the Wups.dll file as Wups.dll.old.

6. Restart the computer.