Install/run on a machine that won't shut down cleanly

[arbarnhart]

I am trying to install on a machine that doesn't close down cleanly, which I am almost certain is caused by whatever is going on. Avast installs, but doesn't run the boot time scan and when run from the menu asks for the key and rejects a valid one. I installed in safe mode.

[DavidR]

Have (or did) you another AV installed in this system, if so what was it and how did you get rid of it ?

What is your firewall ?
Some are very bad in blocking elements without notifying the user they have blocked. One such firewall that comes to mine is online armor, which has been see to exhibit this action.

Are you installing in an account that has admin privileges ?
There is no rush to insert a key as the demo key that comes with the program is good for 60 days unrestricted use.

[arbarnhart]

McAfee is there but not really functional, but uninstall hangs. I am able to run msconfig and turn services off and on and disable startup programs so I have been trying to get it to not have anything running. Avast installs, but if the machine doesn't reboot properly something is wrong with it. It immediately asks for a key if you run it from the menu, won't accept the key (it is valid) and doesn't go on without it.

[DavidR]

Functional or not it can cause issues other AVs when they are installed.

You don't say what version/product of McAfee, so here are some useful links to remove them.
McAfee has an uninstall tool that you could run to ensure any possible remnants are removed.
http://download.mcafee.com/products/licensed/cust_support_patches/VSCleanupTool.exe Or http://majorgeeks.com/McAfee_Consumer_Product_Removal_Tool_d5420.html
2007 version - http://download.mcafee.com/products/licensed/cust_support_patches/MCPR.exe
Also see - How do I uninstall SecurityCenter? http://ts.mcafeehelp.com/faq3.asp?docid=71525

First try and remove McAfee and reboot, see if avast now runs, if not it may be best to do a clean reinstall.
Download the latest version (4.8.1335) of avast http://www.avast.com/eng/download-avast-home.html and save it to your HDD, somewhere you can find it again. Use that when you reinstall.

Download the avast! Uninstall Utility, find it here and save it to your HDD.
1. Now uninstall (using add remove programs, if you can't do that start from the next step), reboot.
2. run the avast! Uninstall Utility, reboot.  If step 1 failed it may be necessary to run this from safe mode, once complete reboot into normal mode.
3. install the latest version, reboot.

You didn't answer the other questions (firewall, admin account), they help us to help you.

[arbarnhart]

Sorry, yes I am admin. I found a utility to get the old McAfee off and I found the major source of the problem - the machine used to be part of a domain and had been disconnected too long for cached credentials to work for some operations. It caused IE and some other windows apps to hang, even though I was logging in to the machine. Once I changed it to say it was no longer part of a domain, things started working again. But when I tried to install Avast again, it says something needs a reboot and reboots the computer whether I answer Yes or No to the dialog asking if I want to reboot. I gave up and installed AVG. I like Avast better for truly trashed machines (I put it on a couple my kids had surfed on and it cleaned them up nicely) but once I figured out that box actually had a configuration problem and not a virus (I have scanned with a few different utilities) I decided that AVG would be fine.