[CentOS] Help on deleting partitions

Hi,

I have this dual boot Vista-CentOS.

I have one NTFS for Vista, and three for CentOS.
I boot to both OS through grub.

Unfortunately, I'm going to need the CentOS space for Vista :( :( :(

So my question is: if I remove the CentOS partitions *from within Vista*
with its tool for it, will I be able to still boot Vista ?

Is grub going to disappear ?

If so, will Vista replace it for its own boot manager, thus allowing to
boot it ?

Or what ?

I've googled about it, but couldn't find a definitive answer and I can't
afford losing my Vista data.

Any help would be appreciated.

Warm Regards,
Mário