I am newbie to ubuntu. Let me make it clear. I have 250GB hard drive. First i installed windows in my hard drive. Then i installed ubuntu by Flash drive. I was using ubuntu less than a day. Then i mistakenly deleted ububtu drive in windows disk management. After that i reinstalled windows. Now windows is working properly. But i tried to installed ubuntu by Flash drive again, its doesnt have any option "install ubuntu along side of windows". The first option is "Erase the hard disk and install ubuntu". But i want windows too. and during that installation process one smaller window open and says "The installer has detected that the following disk have mounted partition blah blah blah ..... /dev/sda". please somebody help me i want both windows and ubuntu. And last one to tell is when i choose ubuntu installer pen drive in boot option a beep sound comes from CPU.
This is most probably because of a problem with your Master Boot Record(MBR). You can use EasyBCD to manually rewrite your MBR from Windows. Try to do the install now. If that doesn't work, since you have made a bootable flash drive, you have the option of using it inside Windows to install Ubuntu alongside Windows just like a normal Windows software. The problem though, is that this mode of installation uses wubi, a relatively simple bootloader and not the better grub. But that shouldn't bother you since you are a beginner and wouldn't require any power user features at the bootloader level.
finally i found that the partitions were already created when i installed ubuntu for first time. so i just choosed the option format /sda partitions which showed in that pop up window. And i re-installed linux. while reinstalling linux those partitions created for first time have been overwritten. Now i have dual boot