I keep getting the same error also. This is a fresh install of Windows; I have tried different download sites, turning off the anti-spyware, disabling the firewall, etc. Haven't found anything yet that works and I've gotten nothing from AVG except they want me to register or provide a registration number (can't do that without the install first!).
I'm continuing my research...
Anyone seen this?
avg free 8.0 build 233 1/15/2009 install kit
Local machine: installation failed
Error: Action failed for file avgtdix.sys: starting service....