Hi…
I right-click the Avast icon down by the clock, choose ‘Start avast! Antivirus’ and then my PC immediately reboots. Any idea what that’s all about?
Regards… Mark
Which other antivirus are you running?
How did you remove (uninstall) your old antivirus?
Any other security program that could interfere?
Which is your operational system?
I’m running no other anti-virus software. I haven’t uninstalled any previous anti-virus software either, this was a clean install of XP a couple of months ago.
XP SP3
Athlon XP3200+ 1GB ram
Avast! v4.8 Home Edition
A-Squared 3.5.0.27
ZoneAlarm version:7.0.483.000
TuneUp Utilities 2007
Ethernet to ADSL+2 Router
Check the folder \data\log
Are there any files called unpXXXX (where XXXX is a random number) or *.mdmp there?
If so, send them to vlk (at) avast.com
They may contain more information about the problem (maybe a link to this thread).
Please, go to folder \windows\minidump and send the newest (recent) .mdmp files for analysis. There is also C:\Windows\Memory.dmp file.
Better if you can compress (zip) them and add some information about the BSOD and the link for this thread. 
Send an email to: vlk (at) avast.com
Or upload it to this anonymous ftp server: ftp://ftp.asw.cz/incoming
Also, Control Panel > System > Advanced > Initialization & restoring Settings > Choose the dump options (removing the autorestart in case of failure)
Thank you for your assistance, unfortunately however I needed to get the PC back to work right away due to time constraints so I reloaded a partition image from last week.
I have used Avast for quite some time and will continue to do so.
Regards… Mark
Backup… a very lovable practice