You can easily install the Windows 7 in your computer after checking and ensuring the system requirements. You can insert the Original Windows 7 OS in your drive and reboot your netbook; this will make your netbook boot from the DVD. Follow the installation wizard and after the installation, enter the product key and then register the product at the Microsoft website.
Get more information to reinstall windows 7 on acer aspire :
It's real easy. Press "Alt F10" at the same time, as the computer is beginning it's boot process, Obviously w/o the brackets.
Thank You So MUCH for this answer. Ricky_Critic obviously doesn't know enough about different brands of computers to know that Aspire One's don't come with cd/dvd drives or repair discs to solve this problem that way.
The Alt+F10 trick is even new to me as I have only just begun working on netbooks with no cd/dvd drives.