8.10 Install question and concern

[slikwill]

I have booted the live cd for ubuntu 8.10 and attempted an Install to a 8GB USB drive specifying:
guided - use entire disk and specifying the SCSI4 (sdb) drive

When I got to step 7 I was concerned because it said:
The partition tables of the following devices will be changed:
SCSI1(0.0.0) (sda)
SCSI4(0.0.0) (sdb)

My concern is that if I continue I will wipe out my hard drive.

I read
Important: Physically disconnect ALL internal hard drives before booting from the CD and performing the install. this will eliminate the possibility of installing to the wrong device and overwriting your MBR.

at Pendrive linux

is my concern the reason to disconnect the internal hard drive?

Any advice would be appreciated

[MykeBuntu]

(I was going to do a pendrive install for a frontend box at one point... still haven't gotten around to it)

But yes-- play it safe unless you don't care if you hose your existing drive -or- if you are absolutely certain the drive it's talking about is NOT your existing drive.