Dual booting ubuntu along with windows7

To install Ubuntu you must get some tools.That is download Universal USB installer from internet. Also you will be needing to download the Ubuntu iso file from the Linux official website. Then use the Universal USB installer to load the ISO file into a pen drive by following the below images. First you will get the below window on running the Universal USB installer. Here choose the ISO file you have in your computer or the one which you downloaded.

 Then after selecting the ISO file which you want to load into the pen drive click create and then you will get the below window.

 Then restart your system and enter the BIOS configuration menu by pressing a function key (the function key needed to be pressed varies with the brand). For Sony brand press F2 to enter the BIOS. There change the boot priority to the External drive and save the settings and exit.Then your PC will load Ubuntu. Here you will be asked whether you want to install or test Ubuntu. If you like to install it on your PC click on the install option or else don't.
After that you can follow the below process.

When you boot the LIVE CD/USB for installation, you will get 3 options like the picture below

for your Requirement,you should click on the 3rd option - Do something else.

That will take you to a partition table.

In the partition table you will see 2 partitions. - The 1st one will be c drive which has windows.You will be able to see it as NTFS file system.

• If both are NTFS,mostly the 1st partition will be C drive.

keeping the size of the 2 partitions different e.g 230 and 270 will help you easily recognize your c drive because there are no labels like c or d there)

Then select that other drive.

Get some free space to install :

Caution : Below steps is for deleting . Deleting a hard disk partition will make all files inaccessible everything in that partition, be sure to take back up if any.

• Select that drive(other than the WINDOWS c DRIVE) from the partition table and click on DELETE. That partition will be deleted and you will see unallocated space.

Caution : Below steps is for formatting. Formating a hard disk partition will permanently erase everything in that partition.

Now,you can either directly make the complete partition as EXT4 for installing Linux or you can also add a SWAP partition.

It is always recommended to add a SWAP area for better performance but only if your ram is below 8gb

Step 1 : Create a SWAP partition

1. Select the new unallocated space or free space, click on add.
2. Assign the space from that partition to SWAP AREA equal to double your ram.(e.g-for 1gb,swap area-2gb)
3. Select SWAP AREA from the file system drop down menu.
4. Make sure Beginning is selected in the partition position drop down menu.
5. Click on add.

Adding root file system

Now, after you have added the SWAP AREA,do this-

1. Select the remaining "Unallocated space" and click on ADD.
2. Select Ext4 Journaling file system from the file-system dropdown menu.
3. Select Primary from the partition type drop-down menu.
4. Select the mount point as / from the mount-point drop-down menu.
5. Select beginning from the Position drop-down menu.
6. Click on add.

After adding the partitions,from the table select the ext4 partition you see and tick in the corresponding check-box(if not already ticked) 

then Select install. That's now you can use your Ubuntu along with Windows or other. Some of the users of Acer brand PC's are facing problems in installing Ubuntu as Ubuntu is trying to certify the different models in each brand. So please make sure that your model is certified by Ubuntu by checking the Ubuntu's official website .