I just installed Ubuntu 11.10 along side with Win7. but it is not showing Operating System select option at boot time, instead it boots to Win7 directly. can anyone help me...
You might have to enter a key combination. Try holding Shift-F8 or F8 alone just after your BIOS screen goes away and before the 'loading windows' screen comes up. You'll have to have good timing, so try at least a few times.
After that you might need to configure the boot loader, but that appears to be beyond your immediate problem for now.