Damnn…got my Hippo’s and Puma’s mixed up.
Thanks @DavidR for the correction.
@DavidR and @Rocksteady: The install aborted very early in the setup, demanded that I restart Windows. I haven’t uninstalled the goofy AVG that claims it expired December 31, 1969. When I initiated that, it offered to “Repair” itself, and changed nothing I could see.
After reloading the OS, and attempting the install again, it tells me about a problem in the Registry – I haven’t loaded RegEdit, I don’t think, since Win2K was a young pup! This is beginning, to me, to look like a boogered up install / setup of Windows XP / SP3, itself! I’m wondering if I should put the CD back in, and install over the top, to see if it will settle things down!
Kiwi, getting a bit aggravated
You’re welcome.
I would say reinstalling windows would have been using a sledge hammer to crack a nut an there would be potential for issues even then as you have experienced Even with the original disk, there would be a shed load of updates and SPs to install.
The first port of call would have been to ensure that AVG is uninstalled, before trying to install any new AV you should always uninstall your previous one. Even if it is a very old installation, if still installed it would need to be removed rebooted, but that probably isn’t an issue now if you have reinstalled the OS.
Without saying what that registry it would be hard to guess at a resolution. So I did a search for fix registry issues after reinstalling windows XP and came up with this.
https://www.google.co.uk/search?q=fix+registry+issues+after+reinstalling+windows+XP
The very first hit may well be a good start point or the two following that.
Avast 18.x would require at the very least you have XP SP2 installed.
And your CPU chip had support for the SSE2 instruction set.
@DavidR: AFAIK, the AMD A64 X2 has SSE2, and the install CD has SP3 already merged into it by Microsoft. Meanwhile, I had errands between visits here to the forum, which seems to be in Britain? The CD is still stored away where I put it earlier this week (Monday? Tuesday?) when I finished the install.
I’d only written the first half of the registry error message location down; I’ve now seen it once again:
Cannot create a sub-key in the services registry. Adjust access rights for 'HKEY_LOCAL_MACHINE_SYSTEM\CurrentControlSet\Services"
The Neo Page your search went to had a broken link for the NTFS reference (MS has killed it off). I don’t have access, not even from the Administrator Account, to the contents of the System Volume Information folder.
Kiwi
@DavidR:
The Neo Page your search link took me to had a broken link for the NTFS reference (MS has killed it off). I don’t have access, not even from the Administrator Account, to the contents of the System Volume Information folder. I’ll see what another source offers … still at it out here.
The Kiwi
Not really sure which you are referring to, I only went to the first 3 hits in the main search, I felt the first appeared related followed that link to https://neosmart.net/wiki/fix-registry/ and that worked just fine.
All of the links on that page are internal and the XP one is also working for me. So you would have to be more specific.
That said it isn’t my intention to give complete information on how to do this, but to give you a search string that picks up several registry fix options that could help resolve a broken/corrupt registry in XP.
The Kiwi, if you are going to use the old computer only to play old DOS games and in light of all the problems you have had thus far, it seems to me that it would be simpler to forego connecting to the Internet and to download whatever you need to the new computer, scan the files using the antivirus installed there, and then transfer them using a flash drive. I would be comfortable doing that, but of course it all depends on your experience and how you feel about it.
If you still experience problems related to the Windows XP installation, an alternative solution could be to install FreeDOS (http://www.freedos.org) on the old computer. I have not tried it myself and there may be advantages to using Windows + DOSBox (I assume DOSBox uses the Windows sound drivers, which could be more straightforward for some games than trying to get sound working under FreeDOS), but I just thought it might work better for you.
Thanks, Dix Huit! The audio emulations are a key component of the Windows plus DOSbox matchup. I’ve been too busy today to pursue sorting the permissions for the services folder in the Registry, I’ll get to it eventually. Since I retired, things are backwards. I have more places to go and things to do weekends than during the week!
Kiwi
Yes, I did a little more looking into FreeDOS, and having audio will usually require the original DOS driver for the sound card being used. So it’s really only suited to hardware of the DOS era.
That Registry problem sounds serious - you might try using XP’s “Administrator” account to do the installation but as you suggested, it seems more like a problem with the installation of Windows itself.
Anyway, I wish you luck. 
It’s a bit off-topic but for notice: Microsoft removed required databases for Windows XP/Vista (more precisely, SHA-1 hashed ones including Windows 7) to use Windows Update, so you can’t use Windows Update for installing patches when you perform factory reset.
Thanks, NON, I halfway expected that would be true! I wonder what will happen when I try to activate the registration (this time). I suppose I could run a search on that; it doesn’t reflect an Avast AV query, exactly!
Kiwi
Kiwi, if “normal” activation doesn’t work for you, there is a Registry trick which has worked for me in the past. It’s a bit complex, but let me know if you want to try it (no guarantee). 
Thank you again, Dix Huit! Although I would have preferred to use an AV that I am used to and have trust in, an Offline Install seemed to be a must, however, it seems it was just not to be the way I wanted.
In order to provide for the occasional exposure, and to see about Activation, I wanted protection before ever plugging in the ethernet cable from the router! The Avast Offline installs I tested had problems. I was forced to choose another AV, regrettably. The Activation went through without a hitch.
All the rest of the helpful folks here, DavidR and Rocksteady, of course, glad to meet you!
Kiwi
You’re welcome, good to meet you and good luck in the new AV.
You’re welcome, and good to know that XP can still be activated. I hope you don’t run into any more trouble and will soon be happily gaming.
Beginning on December 1, 2018, new Avast/AVG Antivirus products will no longer be delivered for the Windows XP and Windows Vista operating systems.
https://forum.avast.com/index.php?topic=220639.0
This means that as of December 2018, existing users on the Windows XP or Windows Vista OS will remain on version 18.8 or older rather than
migrating to version 19.1 scheduled to be released in December of 2018. However, please note that all Windows XP and Vista users will continue
to receive virus definitions updates from the Avast Threat Labs database after this date and Avast/AVG Antivirus versions 18 and older will
continue to work as usual providing full protection, but will not receive regular automatic updates of new program versions with new features.
Crap version 18.8 or older I want the newer version as install the older version does nothing as it won’t install as its to old.
My main computer is Windows XP.
I know what your going to say that’s on old OS, I don’t care if its old it works how I want it to work.
Avast Premium Security 20.5.2415 (build 20.5.5410.561) last time I checked.
Avast Free Antivirus 18.8.2356 (build) 18.8.4084.409)
Free version or now the taskbar icon shows its not protected so the free version doesn’t protect anything?
I can scan a file or folder and it shows it there is a problem.
Virus definitions version: 201114-2
Current version 20114-2
Release date 15/11/18
Latest update 14/11/20
Avast Premium Security 20.5.2415 (build 20.5.5410.561) on my Windows 7 laptop.
So I want the same on my Windows XP computer that is what I pay for.
Which is due for renewal I know.
Subscriptions is another long thread which I have made as bad as Avast is the forum is just as bad for my posts just like Avast itself, its like a Google search. If I made a post it should show the thread I made not what I posted. If I click on the link shown it just opens the thread I have to look at every post to see where I’ve posted my comment.
The ONLY reason I use Avast is because the license can be used on 3 computers. That is the only good thing about Avast.
All other anti-virus companies charge you for every computer you have.
Where to download last version for processor without SSE2? (the above mentioned version (post #1) is not installable)!
I assume you downloaded the offline installer from the links provided.
What error do you get?
The installer files are also available from bob3160’s Google Drive share if needed.
See:
https://forum.avast.com/index.php?topic=220639.msg1533473#msg1533473
Other (old) versions can be found on filepuma. 18.5 is preferred by some over 18.8 which may hog CPU.
https://forum.avast.com/index.php?topic=220639.msg1565331#msg1565331
… error message:
“We are sorry but Avast Antivirus cannot run on your computer because your processor does not support SSE2 instruction set.”
This happens both with online or offline installer and also when running that version of avastclear in the mentioned link (to uninstall an older version).