Windows 7 installation problem :setup was unable to create a new system partition

For answer to this error: “setup was unable to create a new system partition or …” please see this paragraph

Many of us face this problem when we try to install windows 7 on our system. Today I try to format my existing windows 7 operating system  (OS) which was working fine but I was getting some error while working on eclipse for developing  android apps. I googled for solving eclipse problem but unable to get any solution  than I thought I will move to ubuntu which was installed on my system and I use for completing  on my college assignments. When I tried to login on ubuntu I found that I forget my password. I know how to remove password without knowing it (hacking trick I will Share it later), but i preferred to clean my Laptop and install fresh OS copies of win 7 and ubuntu.

Now i got this error “setup was unable to create a new system partition or ……” when i tried to install windows 7 using Bootable USB pen drive as my CD rom was not working. I start well showing me all screens but When I tried to select hard disk partition 0, which contains previous windows 7 copy than it gave me this error “setup was unable to create a new system partition” I search on google and there were many answers like clean your hard disk using command prompt using shift +F10 key and executing some commands like diskpart and clean all etc…by using these methods I may lost my data which I don’t want. but non of them worked for me than i search more pages on installation error and I come to know that If you are having two different hard disks and these hard disks contains any other OS than  you may get this error but On my laptop I have only one disk than why I ma getting this error. Answer for this question is that pendrive is also a hard disk and it contains windows 7 which is booting my system.   what works for me is this.

Solution to this error “setup was unable to create a new system partition”

If your are using Bootable pen drive than it may cause this error so what I did after windows loads its all file I removed pen drive and than follow the other instructions on the screen. It helps me do get this screen on my laptop after fighting for 3 hours. Please comment if this method works for you.  After installation please update your windows for better security.

Windows 7 L ogin Screen