Need to change boot from Ubuntu to Win 7

[piezoelectron]

I have a dual Ubuntu 11.10 and Windows 7 Home Basic booting system on my laptop (VAIO, specs at the end). Each time I switch on my laptop, Ubuntu's GRUB first shows me the options as to which OS to boot from. The choices include Ubuntu and Windows 7. To install Ubuntu, I made a 25 GB unallocated volume on my hard disk. Recently, while updating Ubuntu to its latest version, my internet crashed and the download only partly succeeded. After that, I have never been able to use Ubuntu on my laptop. However, GRUB is still functioning; each time I switch on, I still see the options as to which OS to boot from. If I choose Win7, then I get the usual Windows 7 Booting screen.
Basically, I now have 25GB of space lying unusable on my machine. I want to merge this with one of my other partitions. However, I fear that doing so would delete GRUB and make my laptop impossible to boot.
What steps should I take? Is there any way whereby I can safely delete Ubuntu and change the boot sequence from GRUB to the Windows boot program? (I guess it is BOOTMGR.EXE)​

 

[sgage]

I have a dual Ubuntu 11.10 and Windows 7 Home Basic booting system on my laptop (VAIO, specs at the end). Each time I switch on my laptop, Ubuntu's GRUB first shows me the options as to which OS to boot from. The choices include Ubuntu and Windows 7. To install Ubuntu, I made a 25 GB unallocated volume on my hard disk. Recently, while updating Ubuntu to its latest version, my internet crashed and the download only partly succeeded. After that, I have never been able to use Ubuntu on my laptop. However, GRUB is still functioning; each time I switch on, I still see the options as to which OS to boot from. If I choose Win7, then I get the usual Windows 7 Booting screen.
Basically, I now have 25GB of space lying unusable on my machine. I want to merge this with one of my other partitions. However, I fear that doing so would delete GRUB and make my laptop impossible to boot.
What steps should I take? Is there any way whereby I can safely delete Ubuntu and change the boot sequence from GRUB to the Windows boot program? (I guess it is BOOTMGR.EXE)​

In Windows, download and install (free) EasyBCD. Click on BCD Deployment, then Write MBR. Done!

Or you can boot a Windows Recovery Disk if you have one, and use the repair facility.

EasyBCD is the easiest way to go, I think.