datpalms,
May I offer a suggestion to ease your problem with restricted downloads?
Without info as to your overall system the following is necessarily in general terms.
Before making your new XP SP3,
create a new extra primary partition, say 5GB, on your harddrive.
(Even better, get a second harddrive.)
Install your new XP SP3 into this Partition
(This will automatically create a dual booting capability)
Get xxClone from
http://www.xxclone.com/ (about 5MB)
and install it in your new XP SP3 OS.
Add any vital applications (e.g. security software) to this Basic XP OS
then xxClone the OS to the old partition, thus removing the unwanted version.
Now, in the future your can retrieve a clean OS without incurring download penalties.
This works well for me, and was particularly valuable before SP3,
when SP2 updates to a clean installation were approaching 100MB.
I now can retrieve a clean XP SP3 from my backup clone in about 5mins.
Another benefit is that a cloned OS does not have to be re-activated by Microsoft.
I leave suggestions about saving downloads for Avast! updates to others.
Maurice
p.s. the xxClone forum is here:
http://groups.google.com/group/xxclone