No need for an optical drive.

Your netbook does not come with an optical drive but you can still reformat it using a usb flash drive.

I’ve reformatted a lot of desktop computers, laptops and netbooks since I learned how to reformat using a USB flash drive only. Normally, you need an installation CD or DVD to reformat a computer. But here, you’ll learn how to skip that requirement.

You need the following to reformat using a USB flash drive:

How to reformat netbook using a USB Flash Drive with Screenshots for each step1. The laptop to be reformatted.
2. A USB Flashdrive with at least 4GB capacity.
3. A copy of Windows 7 or other operating system. You can have a copy of Windows 7 from this direct link to their server. 
4. A piece of software called Unetbootin.

Steps in Reformatting Your Netbook

Note: Make sure you have reformatted your flashdrive first and set its format to NTFS for this to work.

1. Download Unetbootin. Install it then run it.

2. Choose Disk Image then browse to the location of the Windows iso file you have just downloaded. Hit OK and wait for the process to finish. This will take about an hour to complete.

3. You now have a bootable flashdrive that you can use to reformat any computer.

4. Boot up the netbook that you have to reformat. Hit Delete or F2 before it starts to go to the BIOS.

5. Go to the Boot section of the BIOS and make sure USB HDD is the first option in the boot priority.

Installing Windows Screenshot

6. Save the settings and reboot.

7. Now, the netbook will boot up from the USB HDD or your flashdrive. Choose the language you want to use during the installation then choose the first large partition to install windows in.

Installing Windows Screenshot

8. Wait for the process to finish and the netbook restarts. When it does, hit Delete to go back to the BIOS and change the boot priority to the main Hard Disk of the unit.
Sit back and relax as windows installs itself.