Hi, I have downloaded the PRO version as a demo because we are thinking of installing on a number of computers. At the moment I am not very impressed. The download is a small file which in turn links to another file to download- this install file does not work if you have another antivirus program running (even Avast home) so you have to uninstall for it to work - leaves computer vulnerable for what seems like ages on a very slow download speed. Eventually it installs, then try finding a way of starting a scan to make sure that while your anti virus was not on your machine you didn’t pick up anything. IF I start the program from the desktop icon OR by right clicking on the A and then Start program- I get a small box that says Start and memory test- whether you stop that scan or let it finish it the says program will now continue and then everything disappears, there are NO file links or tabs on that box. I am totally foxed - has anyone any ideas PLEASE??
Absolutely it shouldn’t work with another AV installed as it isn’t recommended installing a second AV. Nor is going on-line without protection, so we are in the chicken and egg scenario and why I think this small installation option is crazy.
So you should always download the full version, http://www.avast.com/eng/download-avast-professional.html, scroll down (don’t use the Cnet button) to your language version, see image. That way you retain protection until you have the full setup installation file saved to your HDD. Then you can safely go off-line, uninstall the old AV, reboot and then install avast.
You shouldn’t have to start the program, when installed it is resident and should be running on start-up. The desktop shortcut is effectively to be used in safe mode where avast doesn’t start and or to launch the Memory scan followed by opening the on-demand scanner (Simple User or Enhanced User Interface).
The fact that you aren’t getting the Simple(or)Enhanced User Interface appear could be down to the other AV or remnants of it conflicting with avast.
What was the other AV installed in this system and how did you get rid of it ?
It was the free Home version of Avast. I used uninstall in add and remove programs in the XP control panel. I also restarted after uninstalling.
Thanks to Alwil good programmers… two antivirus will conflict.
No, the installer will upgrade the home to the trial (pro) version. It won’t let your computer vulnerable to nothing as the Home version is installed and running until next boot.
Maybe you’re running two antivirus at a time…
You should have downloaded the full installation package so it could be installed off-line and as Tech mentions you would have been able to install over the top and convert to the Pro trial.
No way would it install over the top of the home version, the setup file just did not run. I only have one AV on my machine, I have now managed to get it on my laptop and it is working, but I downloaded the other file package first.
On my desktop, I uninstalled the not working Pro version, then my PC would not load the home version again. I then loaded another free AV on to my desktop and ran a full scan- luckily I had not picked up anything nasty,
Will try to load Pro on the desktop again today- will do a regiistry clean up first.
Hi all, Thanks for your answers, I have solved the problem and now have PRO version running on the desktop. I cleaned all references to Avast and Alwill from the registry and reloaded the software. Hooray it worked !!
Maybe something get messed with the registration data stored in value “RegData” of the key HKEY_LOCAL_MACHINE\SOFTWARE\ALWIL Software\Avast\4.0
Glad you’ve finally succeed. 
Me its not the same version but when i was having a problem with Avast! i just repair or uninstall with the removal tool and control panel and its did great his job. So glad your problem is repaired.