Which of these steps did you take to install Ubuntu on your Windows 7 machine?
1. Try it first without installing
2. Install using the windows installer
3. You booted an install CD/DVD and selected install
Normally, the default option is to install into free space so that you end up with a machine you can boot into either Windows or Ubuntu.
If you went through options 2 or 3, you should (each time you boot) see a boot manager of some kind (like at the bottom of link 2) displaying a list of all the operating systems on your machine. Do you see this?
> I have Ubuntu in windows 7, which is accidentally deleted.
What exactly did you delete?
There is a big difference between deleting a file, and deleting an operating system.
If you managed to delete one (or other) of the operating systems, by say choosing "use whole disk" when you chose to install Ubuntu, then all your windows stuff is truly gone. You either need your windows installation CD, or a recovery partition
I guess you have access to another machine (which is where you posted from). The important thing is to do NOTHING
without fully understanding what you're about to do. If there is anything to save, then trying random things could make things worse.