[plug] grub.?

[James Elliott - WA Rural Computers]

I have two hard disks, one running under Windows XP
and the other Ubuntu Linux.

I want to replace my Windows XP HDD with a bigger one.
For this purpose I temporarily replaced my Linux HDD with a new 250MB HDD, 
with a view to cloning my old Windows HDD onto the new HDD.

Trouble is that I use GRUB boot manager to choose between Windows and Linux, 
and when I remove the Linux disk and attempt to boot, I get a black screen 
error message saying something like:

GRUB boot error 5 ... please wait

To enable me to boot my computer again and send this message, I have had to 
reinstall my Linux HDD.
Can anyone tell me how to get rid of GRUB, at least for the time being.

Many thanks,  James