I NEED HELP! Cannot access external drives!

I NEED HELP! ACCESSING EXTERNAL DRIVES

This is a problem that came up about two months ago.
Before that, no problem.
I use:
Win XP Home Ed SP-3

When I access an External Drive using USB, (Flash drive, camera,
backup portable drive, etc.) it is recognized and assigned a Drive
Letter. It shows the folder icons.
However when I try to access (open any files) I get the message

"This Operation Has Been Cancelled Due to Restrictions in Effect on This
Computer. Please contact your system administrator"

I have tried looking at every check box that I can find to no avail.

Another suggestion was that I install "GPEdit" Did that.
Could not find any place that would lock or unlock file access.

Since I use home edition I cannot access any "security" tabs.
Trying to boot into "safe mode" only brings up a screen that asks me
what disk I want to boot to. Selecting any disc besides the disk
my "C" drive is on does nothing. Selecting the "C" drive disk starts
XP normally.

I am at my wits end. As far as I know I did NOTHING that would cause this.
Without being able to access my external drives this machine is rapidly
becoming useless to me.
I have spent dozens of hours trying to track this down.
SOMEONE must have heard about this problem before and knows a
simple solution to it.

PLEASE!!!!!
Thanks
Mark