Deleted Windows Partition with Boot Files

I'm running a dual-boot setup with Windows 7 and Ubuntu. I accidentally deleted the partition that contains the boot files for Windows.

Here is my output from fdisk -l in Ubuntu:

/dev/sda1   *   330545152   369606655    19530752   83  Linux
/dev/sda2        36944325   330543151   146799413+   7  HPFS/NTFS/exFAT
/dev/sda3       428199936   812201983   192001024    5  Extended
/dev/sda5       428201984   447868927     9833472   82  Linux swap / Solaris
/dev/sda6       447870976   812201983   182165504   83  Linux

Key Partitions: sda1: Ubuntu sda2: Windows data sda6: Ubuntu data partition

When I select sda2 from GRUB, it says <Windows ROOT>\system32\hal.dll is missing (obviously this does not boot, since this is the data partition).

When I try to boot from a Windows 7 recovery disk, I get this error:

Windows has encountered a problem communicating with a device connected to your PC.
This error can be caused by unplugging a removable storage device, or by faulty
hardware such as a hard drive or CD-ROM. Make sure any removable storage is properly
connected and then restart your PC.

File: \Boot\Bcd
Status: 0xc00000e9
Info: An unexpected I/O error has occured.

I don't have the Windows 7 install DVD, or any type of recovery partition. Also, I accidentally formatted over the Windows boot partition, but have not written data to it yet.

Is it possible to recover the Windows boot partition or to re-install boot files without buying a DVD?

From your ubuntu installation you can try using testdisk (you can apt-get install testdisk)

It was primarily designed to help recover lost data storage partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally erasing a partition table).

Recovery of a lost and damaged NTFS