Lester,

System Restore (SR) is a mechanism which tracks changes and allows a user
to return their system to the state it was in at a particular point in
time when a checkpoint was created.  The system will only roll back if the
user chooses to do so, SR won't do this spontaneously nor will it make any
attempt to prevent the replacement of or removal of any file although
system file protection may well do so.

Let's take the case of a software of driver install.  Many install or
updates will automatically create a checkpoint but not always so I usually
advise users to make one manually.  Now make that installation or update.
If all is well then continue.  If not then the user has the option of
uninstalling the update.  Where SR comes into play is if the update does
not uninstall correctly and perhaps leaves the system in an unstable state
as may well be the case when removing some malware.  There is also the
case where the update or install has no uninstall option such as say when
installing WMP9 on Win Me.  At this point the user has the option to
either reinstall their system from their backups, assuming they have a
recent backup, or using system restore.

Using SR to roll back to a checkpoint created before the install will a)
remove all files added by that procedure with an extension monitored by SR
(See FileList.xml for a list of the 550 odd SR monitored extensions), b)
restore the original version of any file deleted or amended by the install
(same 550 monitored extensions), and c) restore a copy of the three
registry files (user.dat, classes.dat and system.dat) as well as win.ini
and system.ini that were archived at the time the checkpoint was created
(similar to the actions of SCANREG /RESTORE from Win 98/98SE and still
available in Win Me).

Disabling SR won't aid the removal of any application or driver but
disabling it will mean that the user will be throwing away a potential
lifebelt that could be used to restore a damaged system to a known
functioning state.  Once the system is running "sweetly" clearing the SR
archive will remove any unwanted checkpoints and remove the possibility of
the user inadvertently restoring their system to an unstable checkpoint.
I an unaware of any circumstances where SR has spontaneously restored a
system to an earlier checkpoint.  Nor will SR ever prevent the
installation or removal of software or a driver.

Regards,