Hey Gang, I have an older computer that I built for a Senior Citizen (AMD 1.2, 1GB Ram, ATI Radeon 9800 Vid Card, 80GB HDD). I am a repair tech, so we can bypass the newbie stuff, I’ve spent hours on this problem. For starters, we previously had Avast on this computer with no probs at all. Puter was starting to get a bit sluggish, so a few days ago, I wiped the hdd, and did a fresh install of XP. Got all the Windows Updates, all the newest drivers, ran a full Scan Disk, installed a printer, Firefox, and that’s about it. I tried to install the newest Avast Free (eventually from several different sources) and every time I try to install, it unzips, does a system restore, I get the opt-in screens, then I get “Install failed”. I checked the install log, and it says, “install failed-invalid file error”. Again, I’ve downloaded it from several different sources, tried it as administrator, in safe mode, everything I could think of. After the re-install of XP Pro SP3 and updates, system is tons faster, so I accomplished what I wanted, but this Avast thing is killing me. ANY IDEAS, ANYONE???
So is it working now or not…??
Welcome to the forum. 
Try getting it from the source:
http://files.avast.com/iavs5x/setup_av_free.exe
Asyn, Computer runs great, problem is Avast.
Which avast!..?? (Free/Pro/IS)
Which version…??
OS…?? (32/64 Bit - which SP)
Other security related software installed…??
Asyn, XP Pro SP3 32-bit (and every available windows update), Avast 6 Free(not sure which build, but it’s the one I got TODAY from the Avast website, one from CNEt, one from MajorGeeks, one from SoftPedia, etc. get the picture). No other security software installed. Again, fresh install of windows and Service Packs. It’s the procedure I use on EVERY puter I build, before installing any other software. My process insures I’m in a protected environment before I even approach user programs such as Office, or games. I get all my downloads from the manufacturers website whenever possible.
I even tried previous versions of Avast, but still the same problem.
Did you try Bob’s link, as it’s from the official Server…??
At this point I’d suggest that you remove any traces left on your system
from all of the failed instalations using the following tool:
http://files.avast.com/files/eng/aswclear6.exe
Once that’s done, reboot your system.
Next install avast!6 from the download you made from the previous link I posted.
Again, reboot the system. That should take care of things.
Pleas report back.
Asys, I’ve already run the “Clear” program, with every failed install. But, I haven’t tried the download you suggested. So I’ll do that, run the “Clear” program first, then come back and post my results. I’m gonna predict that I’ll get the same results, so PLEASE be thinking about any other possible solutions. I’ve been a repair tech for a long time, going back to Windows 3.1 so this certainly is not my first Rodeo. But, my experience also tells me to step back and seek other opinions when I get stumped. So thanx, and I’ll be back.
What do you mean by the text I bold-ed? There is a System Restore happening during the installation process?
Did you follow these instructions…??
http://www.avast.com/uninstall-utility
I put my two cents in.
Do you have Microsoft Visual C++ 2008 Redistributable installed on your Win XP system?
Avast needs it to run.
First, Gargame, when you do an Avast install, the first thing it does is set a Restore Point, I got past that.
Secondly, Bob, yes did all that.
Third, Tetsuo, Didn’t even get that far, and here’s why:
Asyn, I went back and read every post to make sure I didn’t miss anything. Something you said in your second post sparked my plug, about other security software. I first tried to install Avast as soon as XP was loaded, BEFORE I applied the service packs. That install failed, and I got curious. I installed and ran MalwareBytes, it found nothing, so I uninstalled it. I figured Avast couldn’t install without the XP service packs. So I applied them, and it still wouldn’t install. The mistake I made was assuming that MalwareBytes totally uninstalled itself. For whatever reason (and this has NEVER happened before, with over 100 install/un-installs) it left the MBAM service behind, and it was still running as a service. I shut that down, set it to “Disabled”, ran the “Clear” program again, re-booted, and Avast installed painlessly. Now I just have to go into the registry and find what’s starting the Mbam service and where it is, and get rid of it all.
Sorry gang, to have wasted so much of your time. The old rule about “assuming, making an ass out of me” has struck again. I’m normally very thorough in my diagnostics, but since MalwareBytes has NEVER done that to me, I simply missed it.
Again, my apologies to all of you. Lesson Learned!!!
In fact, the latest SP of that package is needed, but only in certain cases / conditions avast won’t be able to install (meaning, only in certain cases the user needs to download and install the package “by hand” before installing avast).
@MediaGuy1974,
Partial list of removal utilities for security tools:
http://singularlabs.com/uninstallers/security-software/
NP MG1974. 
Ok, that makes sense, thought you meant something else.
No apology needed, thank you for taking the time to work with us as well.
;D You Guys Are The Best ;D
Thanks for this compliment.
Regardless of what it took, happy to know that avast! is finally installed.
I think most of us learned something from this.
I’ve never had a problem with MBAM interfering with an avast! installation.
Live and learn.
When I updated my MalwareBytes Free to the new program version, there was an issue with it not running. I had to uninstall, and run http://www.malwarebytes.org/mbam-clean.exe. On reinstall, MBAM free ran fine. I’d never had to do that before on updates.
At any rate, glad you have it sorted now.