First use Windows 'Disk Cleanup' to create more space on your C: drive.
Description of the Disk Cleanup Tool in Windows XP:
http://support.microsoft.com/kb/310312

Next: Empty the Recycle Bin.

You can also free up more disk space by reducing
the number of 'System Restore' points:
Select Start/Control Panel/System, then in the System Properties window
click on the System Restore tab.
Next select the drive letter where Windows is installed (usually C:),
Then click on the Setting button
Now in the Drive Settings window move the Disk space usage slider to the
left to reduce the amount of drive space System Restore points will use.
This will remove some of the older restore points and free up some space.

Disable Hibernation and delete hiberfil.sys file (If you have it enabled):
http://www.mydigitallife.info/2007/10/25/how-to-delete-and-remove-hiberfilsys-hi
bernation-file-in-windows-xp-and-vista/
and:
http://www.microsoft.com/windowsxp/using/mobility/getstarted/hibernate.mspx

Next if you still need more space:
Remove the files used to uninstall updates to Windows
These folders and associated files in these folders are safe to remove,
however once deleted you will no longer be able to un-install a patch or
update that was associated with the deleted folder/files.
I would keep the most recent set (last two months just in case) of folders
and delete the older updates.
As a safety net I burned these folders to a CD before deleting them.
These files are located in the Windows folder and have folder names
like $NtUninstallKBXXXXXX$.
They are hidden folders so enable viewing of hidden files in Windows
Explorer.
Warning: One folder you should not delete is: $hf_mig$
Also See Doug Knox's page on this issue:
http://www.dougknox.com/xp/utils/xp_hotfix_backup.htm

Finally - You can reduce the size of the Internet Explorer Disk Cache:
How and Why to Clear Your Cache:
http://www.microsoft.com/windows/ie/ie6/using/howto/customizing/clearcache.mspx
Just follow the instructs but instead of increasing the size (as stated in
the article) decrease it.

If you have more than one partition or drive then:
How to Change the Default Location of Mail and News Folders:
http://support.microsoft.com/kb/175037

Change the Default Location of the My Documents Folder
(Example: move it to the D drive)
See: http://support.microsoft.com/kb/310147
Also:
http://www.techsupportalert.com/how_to_move_my_documents.htm

How to move the Spool folder in Windows XP
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q308666

JS

Don

You will need to watch System Restore. During the Update process it
creates a restore point of what exists before the update and a second of
what exists after. The one before is very large i.e. on my system 798 mb
compared to 42 mb after. After installation you can compress restore
points and on my system the 798 mb reduced to 495 mb. In my opinion you
need to retain the restore points for a while as if it emerges that you
have a problem then removal will prevent you easily undoing the update.

JS has made a number of suggestions. In the light of what I have said
above I would ensure that the disk space allocation to system restore is
at least 1 gb. Then
select Start, All Programs, accessories, System Tools, Disk CleanUp,
More Options, System Restore and remove all but the latest System
Restore point. You can then compress the contents of the System Volume
Information folder in Windows Explorer by right clicking on the Folder
and selecting Properties, General, Advanced, check box before Compress
Contents to save Disk Space, OK, Apply, OK.

In Outlook Express place the cursor on Local Folders and select File,
Work Offline followed by File, Folder, Compact All. Do not attempt to
interupt or stop the process until it has completed. Close Outlook
Express when it has completed.

If you have cCleaner then run it otherwise elect Start, All Programs,
Accessories, System Tools, Disk CleanUp to Empty your Recycle Bin and
Remove Temporary Internet Files. Running Disk CleanUp after compacting
Outlook Express is important as the compacting process fills the Recyle
Bin and you need it empty before running the SP3 update.

Two other suggestions which are worth mentioning but I suspect will not
help with free disk space for the SP3 update.

Another default setting which could be wasteful is that for temporary
internet files, especially if you do not store offline copies on disk.
The default allocation is 3% of drive. Depending on your attitude to
offline copies you could reduce this to 1% or 2%. In Internet Explorer
select Tools, Internet Options, General, Temporary Internet Files,
Settings to make the change. At the same time look at the number of days
history is held.

The default allocation for the Recycle Bin is 10 % of drive. Change to
5%, which should be sufficient. In Windows Explorer place the cursor
on your Recycle Bin, right click and select Properties, Global and
move the slider from 10% to 5%. However, try to avoid letting it get
too full as if it is full and you delete a file by mistake it will
bypass the Recycle Bin and be gone for ever.

If you have the capacity to move files from C to another location here
are some further suggestions.

You can generate more space in the system partition by relocation of
folders.

For Temporary Internet Files select Start, Control Panel, Internet
Options, Temporary Internet Files. Settings, Move Folder.

To move the Outlook Express Store Folder select in Outlook Express
Tools, Options, Maintenance, Store Folder, Change.
http://www.tomsterdam.com/insideoe/files/store.htm

How to Change the Default Location of the My Documents Folder:
http://support.microsoft.com/?id=310147

You may also need to change Default File locations in the Microsoft
Office programmes you choose to move the My Documents folder. For Word
go to Tools, Options, File Locations, highlight Documents, click on
Modify and change file path. For Excel go to Tools, Options, General
and change default file path.

My Documents is one of a number of system created Special Folders
including My Pictures and My Music. These can more easily be relocated
using Tweak Ui. Download TweakUI, one of the MS powertoys, from here:
http://www.microsoft.com/windowsxp/pro/downloads/powertoys.asp

In TweakUi select My Computer, Special Folders. You can scroll down to
see the full list of Special Folders to the left of the Change
Location button.

You can move programmes but to do this you have to uninstall and
reinstall.

--

Hope  this helps.

Gerry
~~~~
FCA
Stourport, England
Enquire, plan and execute
~~~~~~~~~~~~~~~~~~~

Thanks to both JS and Gerry-

I had deleted some programs and ran a lot of the cleanup suggested, but not
all, and I had not moved some of the default folders as suggested.  I will
to that next.

One worthwhile comment was that during the installation of the service pack,
more than one restore point is generated.  I did note that things were going
along merrily, nearing what I thought was the end, and all of a sudden the
available space on the drive dropped dramatically.

I'll do the things suggested, do a cleanup with the downloaded cleanup
program available from Microsoft and see just what happens.

Thanks again,

DAW
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