MiKTeX and proTeXt ⇒ Miktex 2.9 not updating packages in Windows 7

[ansimal]

I have been using TexMaker 2.1 with MikTex 2.9 installed on a Windows 7 machine since last 2 months.
I have not had any problems updating new packages till day before.
I was in my college where a proxy is used. I updated the http_proxy environment variable for Windows and then it worked for a day.
After that when I have tried running the same latex file from home where there is no proxy server, it does not compile in Texmaker.
I have tried the following :
- removed the http_proxy environment variable.
- uninstalled the MikTex 2.9 and installed the basic version again.
Now when I tried compiling in Texmaker, I got the following error :
"latex: Host not found latex: Data: get proxy host by name failed in tcp_connect()"
I opened the MixTex package manager ( by running mpm.exe ), and tried to install the 'tabbing' package manually, but now the Miktex package manager gives the following error :
----------------------------------------------------------------
MiKTeX Problem Report
Message: Host not found
Data: get proxy host by name failed in tcp_connect()
Source: Libraries\MiKTeX\PackageManager\PackageManager.cpp
Line: 1534
MiKTeX: 2.9
OS: Microsoft Windows 7 Enterprise Edition, 32-bit (build 7600)
SystemAdmin: no
PowerUser: no
Root0: C:\Users\Anupama\AppData\Roaming\MiKTeX\2.9
Root1: C:\Users\Anupama\AppData\Local\MiKTeX\2.9
Root2: C:\ProgramData\MiKTeX\2.9
Root3: d:\Program Files\MiKTeX 2.9
UserInstall: C:\Users\Anupama\AppData\Roaming\MiKTeX\2.9
UserConfig: C:\Users\Anupama\AppData\Roaming\MiKTeX\2.9
UserData: C:\Users\Anupama\AppData\Local\MiKTeX\2.9
CommonInstall: d:\Program Files\MiKTeX 2.9
CommonConfig: C:\ProgramData\MiKTeX\2.9
CommonData: C:\ProgramData\MiKTeX\2.9
------------------------------------------------------------------
Can someone please help