Can't Boot in windows 7 after installing Ubuntu

I have Dell inspiron mini 1012 with windows 7, It was working fine and now I need to learn ubuntu so I tried ubuntu with bootable pendrive and it was working fine so I thought lets install it.

I installed it and it was working fine. But during installation I selected something else, now when I boot it gives no option of my previous windows 7 OS.

Solution 1-Reinstall Windows bootloader form Windows 7 DVD/USB and go to Repair

System Recovery will automatically start scanning to see if there’s an existing Windows install with something it can easily fix automatically.

If your only problem is the boot loader, often it will automatically detect the problem and offer to fix it.  If so, simply click Repair and restart, and your computer should be booted back into Windows as normal within minutes.

Solution 2 If u can't find ur OS in System Recovery Option

Don't panic , 

just go through this site

http://support.microsoft.com/kb/927392

Solution 3:- With Diskpart

Boot with Windows 7 installation DVD, select repair and open a command prompt.

Type diskpart

Type select disk 0

Type list partition

then note the partition number where you installed windows 7.

Type select partition X    (X is the partition number where Windows is installed)

type active

type exit

type bcdboot c:\windows     (if C is your windows partition)

System Restore From Bootable Pendrive or CD/DVD

Windows System Restore is a useful feature to recover  with the problematic changes that happened with your computer/laptop. But what if the computer can't boot and you don't want to install a new copy of windows.
Problems like

• After installing antivirus or updating an antivirus the computer hangs on the login screen or hangs after the login screen
• Computer can't start in Safe Mode

Solution

1. Bootable OS for accessing File system :-

The easiest way to do this is to create bootable OS using CD/DVD or USB. This could be a Windows PE type disk such as bartpe, reatogo, or hiren. Or even a linux flavor such as knoppix.

If those aren't available, you can also slave the hard disk to a working system. The goal is simply to access the filesystem.

 How to Create Bootable USB Pendrive

     2.  Backup Current Config Files:- 

              Go to C:\windows\system32\config and create a folder called backup. Copy everything in            the config folder into the new backup folder just for safe keeping. If you don't want to copy            everything (such as event log files), then only backup the following files: system, software,            sam, security, and default.

           Note:- Enable viewing Hidden Files

     3.   Access "C:\System Volume Information " and Backup Files

             Change your "View" options to show details so you can sort the files/folders by date                     modified or created. Go to the most recent folder created BEFORE the issues had                     arisen. Inside that folder is another called "snapshot."  Open it and copy the following to a           temp directory:

           _registry_user_.default 

               _registry_machine_security 
               _registry_machine_software 
               _registry_machine_system 
               _registry_machine_sam

     4.  Rename Recovered System Files

           Now in the temp directory, rename them to:

           default
           security
           software
           system
           sam

    5. Copy To "C:\Windows\System32\config"

           Copy those 5 files to C:\windows\system32\config, replacing the existing files in that                    folder (permitting you backed them up in step 3).

     6.  Reboot

          Shutdown the OS you were using and/or reinstall the disk to it's original computer (if you             didn't use a bootable OS CD/DVD).

          Start the computer back up. It should now be booting with the system files you manually               recovered from the system restore files.

Now you have successfully Manually Restored your computer.

Mouse or Emouse

Still many of you may be using wired mouse for your laptop and facing the difficulty same as mine it doesn't works because the wire being folded now and then...
So I found it useful if we remove the cable and use a data cable !!!

when u will open the mouse you will find the circuit like the one which is shown in the figure I have cut the wire and placed besides, look carefully I have opened the usb male you will find four different coloured wires over there soldered.

now see the next figure in which I have attached mini usb socket. the socket is easily available in the market and its very cheap also.....
Now solder the wires into the mini usb but remember the supply wires are always on sides of the usb and the D+ and D- inside...

now put the circuit back into the case and try to attach the mini usb with the adhesive