Restore Point Question

For a little while now, I've been periodically and randomly losing my System Restore points. I've finally concluded it may have something to do with my hardware setup. My system drive is quite small (80GB) and running XP SP3. However, I also have two external drives attached and running all the time. One is 1TB and the other is 2TB. These externals are for backup and redundant backup purposes only.

I just noticed in my System Restore tab that all three drives (system and two externals) are all being monitored. Because the two externals are backup drives only, is there any reason for these to be "monitored?"

I'm not positive, but I'm thinking this might be why I'm losing my System Restore points. It may simply be a "space" issue on my system drive.

Using Windows Explorer select "Computer", right click and choose Properties.

That allows you to choose "System Protection" under Windows 7, and a similar name under XP.

This allows me to individually select for each partition Drive whether to turn "Protection" (W7) or "Monitoring"(XP) to OFF or ON.

On my XP system I quickly decided that when I delete a backup file from my backup partition,

I do not need System Protection to waste a few minutes of my life by intercepting that simple deletion,

as it makes a duplicate copy of a multi-Giga-Byte file in a Restore Point.

On XP only C:\ is monitored - the other partitions are not at risk from calamitous Windows Patch Tuesdays,

and I just take care to avoid deleting what might have future use.

On W7 All protection is OFF.

I got fed up with XP not remembering whether or not a particular file was "User Data" that should not be protected,

and I have far greater confidence that anything short of hardware failure is immediately restored with a Macrium Rescue Boot CD,

and on total hardware failure a similar set of hardware will instantly work after restoring the last Macrium image.

That's what I was thinking, but I wanted another opinion.