Google Answers Logo
View Question
Q: Reserved System Space ( Answered 5 out of 5 stars,   2 Comments )
Subject: Reserved System Space
Category: Computers > Operating Systems
Asked by: rainman999-ga
List Price: $10.00
Posted: 04 Nov 2006 09:51 PST
Expires: 04 Dec 2006 09:51 PST
Question ID: 780063
What is Reserved System Space?
Can I delete the Reserved System Space and if so how? Or at the very
least reduce its size.
I see it labelled in blocks when I use my defragment program; it uses
a massive amount of my hard disk. Also it is on BOTH my C and D

Request for Question Clarification by denco-ga on 04 Nov 2006 17:10 PST
Howdy rainman999-ga,

Please check the following and see if it reduces the Reserved System Space.

- Right click on "My Computer"
- Left click on "Properties"
- Click on the "System Restore" tab at the top
- Click on the "Settings" button
- Move the slider until it is set for around 700MB

Report back here the results of your deframentation program.  Thanks!

Looking Forward, denco-ga - Google Answers Researcher

Clarification of Question by rainman999-ga on 05 Nov 2006 08:58 PST
Hi, checked that, I had turned System Restore off but I went into the
set-up and turned it on and reduced the amount allowed and then turned
it off again. Unfortunately it made no difference. Any other
suggestions I can try?
Subject: Re: Reserved System Space
Answered By: denco-ga on 05 Nov 2006 12:02 PST
Rated:5 out of 5 stars
Howdy rainman999-ga,

The Reserved System Space is space set aside for the Master File Table (MFT)
and it would be a bad thing to eliminate it, and there is no need to do that.
It might be possible to reduce the size of the MFT, but again, there should be
no need to do that either.

The Diskeeper defragmentation program, which you might be using, has a help
file entry on just this topic.

"Green/White striped areas show space on the volume reserved for expansion of
the MFT. This space is reserved when a volume is formatted, and cannot be used
by applications, including Diskeeper. However, the operating system will write
files to this area when the volume becomes extremely full and no other free
space is available. Windows provides the capability for Diskeeper to move files
out of this reserved area, but does not allow Diskeeper to move files into it.
These areas appear only on NTFS volumes."

In other words, just because the space is "reserved," it doesn't mean it is not
going to be usable or used, or that it is going to waste.

The above said, you might be able to reduce the size of the MFT, but there are
some steps that should be followed, and cautiously at that.  You should read
the following Microsoft Knowledge Base (KB) articles carefully and in detail
for more information.

"Adjusting the MFT"

"How NTFS Reserves Space for its Master File Table (MFT)"

Please note that the latter article states the following: "NOTE: This is a
run-time parameter and does not affect the actual format of a volume. Rather,
it affects the way NTFS allocates space on all volumes on a given system.
Therefore, to be completely effective, the parameter must be in effect from the
time that a volume is formatted and throughout the life of the volume. If the
registry parameter is adjusted downward or removed, the MFT zone will be
reduced accordingly, but this will not have any affect on MFT space already
allocated and used."

The bottom line is that adding or modifying the registry entry mention in the
latter KB aarticle might not succeed in reducing the size of the MFT.

If you need any clarification, please feel free to ask.

Search strategy:

Google search on: "Reserved System Space" reduce

Search on Microsoft site for: NtfsMftZoneReservation

I also examined the Diskeeper manual as noted above.

Looking Forward, denco-ga - Google Answers Researcher
rainman999-ga rated this answer:5 out of 5 stars and gave an additional tip of: $5.00
Very detailed, thank you. One point though, I thought Google answers
sent you an email when there was a answer to the question, as I'd have
looked earlier if I knew they'd stopped wending them.
Once again many thanks

Subject: Re: Reserved System Space
From: usrhlp-ga on 06 Nov 2006 02:03 PST
My advice is, do not play with this and do not touch it :D
Subject: Re: Reserved System Space
From: denco-ga on 07 Nov 2006 23:54 PST
You are most welcome, Paul, and thanks for the 5 star rating and the generous
tip.  It is all most appreciated.

Apologies on the lack of email notification of requests for clarification or
an answer to your question.  This has not operated for quite awhile and it is
beyond the control of the Google Answers Researchers.

Looking Forward, denco-ga - Google Answers Researcher

Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  

Google Home - Answers FAQ - Terms of Service - Privacy Policy