Hi - does anyone know if I can install a second XP OS on my second hard disk such that only one disk is accessable on each boot up?

I won't be invisible by default. But you could go into each OS and unassign the drive letter for the other installation/disk via disk management.

AJZ

Thanx AJZ, - Would this prevent viruses and spyware from accessing the unassigned disk?

That is correct. If you need any help removing the drive letter let me know.

AJZ

Thanx AJZ, - Would this prevent viruses and spyware from accessing the unassigned disk?

what are you going to use the second OS for ??????????? if you don't plan on using it on the net ,you could go with a hdd cage, 2 actuall install one and use the iner part of the other for the second drive ,
http://www.storcase.com/removable/removable_overview.asp

You can also set the NTFS permissions such that one OS cant access the drive of the second one.

Done & Thnx. Reason for 2nd exclusive OS is a son who doesnt beleive in worrying about spyware or viruses.

You can also set the NTFS permissions such that one OS cant access the drive of the second one.

I thought NTFS permissions are stored on the disk itself. If you set deny permissions in one OS, the same permissions will apply to the other OS too. For example, if you have XP on C: and D:, and if you set deny permissions to D: from the OS installed in C:, you will not be able to even boot the OS installed in D:. The same applies the other way too. I don't think NTFS permissions are the way to go in this case. Best bet is to remove the drive letter from disk management.

I think the best solution is the removable caddy,2 hdd ,2 windows installs . ,shutdown take your out ,put it away ,let son install his when he uses the computer .

Maybe get a "Hard Drive Switch". - Google ftw