Please use the full AVG installation file (direct link) http://free.avg.com/download-file-ins-afg-free instead of the download manager version to check, if installation will be then successful.
Else please provide us with information about amount of free operating memory during AVG installation and other installed protection application.
I have tried several times to download AVG; I keep getting error messages; I ran malware to get rid of "stuff"; it almost made it but the last message I got was:
Local Machine: installation failed
Instillation: Error: Action failed for the avgldx86.sys.starting service...HRESULT Oxc0078104
Previous error codes: Oxe001C065; Oxe0010045; Oxe001C065; Oxe001C064