Internet Connection is being shown but not openeing any site - Ubuntu 9.X

Open FirexFox in Ubuntu and type about:config
Find the entry network.dns.disableIPv6.
Double click this entry would change its value to 'true'
Rebooot pc and internet would work.

Please visit the below link for more information
https://help.ubuntu.com/community/WifiDocs/WirelessTroubleShootingGuide

Use Ubuntu with Windows Vista 32 Bit - How to solve booting problem

Problem: Installed Ubuntu 9.X on a USB from a pc having Windows Vista (SP2-32bit) installed. After installation of Ubuntu tried to boot Windows by selecting HDD from Bootup menu. It failed and prompted following :
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GRUB LOADING
Error:no such disk
Grub Rescue>
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Connected the USB which I used to install UBUNTU and it displayed boot up menu from GRUB. This menu showed options related to Ubuntu and one option for Windows Vista. When selected Windows Vista option it booted up normally.

Solution : This was happening because the Windows Boot Loader was changed to GRUB Loader in BIOS. I followed below steps to change Boot Loader from GRUB to WINDOWS.
1). Started Pc with the WINDOWS VISTA media.
2). Selected 'Repair mode'.
3). Select Command prompt and run command bootrec/fixmbr to fix the master boot record.
Visit following links for more information
http://support.microsoft.com/kb/927392 and
http://www.bleepingcomputer.com/tutorials/tutorial147.html