grub2 - How can I boot into Windows from GRUB rescue without a CD drive?

This is my situation:

I Installed Ubuntu without a CD (using A USB)
Dual boot installation (Windows 7+Ubuntu)
I did not like the installation and decided to boot into Windows and delete the Linux partitions, but I forgot to fix the mbr from within Windows.

Now, when I boot, I am stuck in the GRUB rescue limbo.

How can I boot into Windows from GRUB rescue?

I cannot boot from CD because I don't have a CD drive, therefore the usual solutions (recovery CD etc) do not work.

Any hints? Is there a way I can maybe do this through a USB?