Windows 7: Restore system partition content

Hello!
I instelled kubuntu on a disk with Windows 7 installed. During the setup, I accidentally formatted the ~200MB partition with windows 7 boot files. The partition is still there, and I can access to it and to the windows 7 main partition. But Windows 7 (obviously!) doesn't boot!
How can I restore the content of this partition?
The Windows 7 dvd didn't work because can't recovery the boot files..
Thanks.

To recreate the separate System REserved partition, which conveniently place the Repair Console normally on the DVD or REpair CD on the F8 Advanced Boot Options:

Mark the partition Active using Diskpart from the DVD System Recovery Options Command Line: Partition - Mark as Active or using free Partition Wizard bootable CD.

Now boot back into the DVD Repair console, accept any offered Repair. When Windows 7 won't start, boot back in again to run Startup Repair from the Options list up to 3 separate times with reboots until the SYstem Boot files are written to the boot partition and Windows 7 starts on its own.

If you have problems with this, take a camera snap of the drive map and listings using free Partition Wizard bootable CD and post it back here. You can also use PW CD to mark Active and confirm you are attempting to write to a Primary partition.

Sometimes the System Reserved partition cannot be recreated in which case you can mark the Windows 7 partition itself Active to run the REpairs and start it. Make sure it is not a Logical partition using PW CD, which can Modify>Convert to Primary if need be.

I have a GRUB boot system installed on computer in a linux logical partition.
Windows 7 and Linux was booting correctly until I formatted the first partition: system reserved partition (200Mb). (very stupid mistake)
Now linux and GRUB works perfectly but the windows option is not working because the boot file are missing.
If I'm not wrong, I should restore the first partition without modifying the MBR (which should point to the logical partition).
Running the Startup Repair from the installation DVD could overwrite the MBR deleting the chance to boot with GRUB?
Is there an utility to just restore the system reserved partition?
thank you.

Try this.

System Reserved : Create Using Disk Management

Is it possible to restore only the system reserved partition without touching the windows partition or any boot loader in a linux partition?
Now I have:
- a formatted 200MB partition
- a windows 7 partition
- extended linux partition with the bootloader GRUB
I can't boot windows but Grub and linux are working correctly.

I doubt it. Restoring SysReserved as given in my post above will likely supercede GRUB unless GRUB has already corrupted things as it will do when on the same HD with Windows 7.

I would install EasyBCD 2.0 (older versions are still free) and try adding Windows 7 using the Linux tab to see if you can do it that way.

Dual boot Ubuntu-Win7

Your ubuntu install may have already rewritten the MBR.
If at some stage you decide to clean (zero) the MBR prior to fixing only clean up to the partition table (do not wipe the partition table).