It should take far less than that or possibly even longer depending on your internet Connection type and the routing from the AVG server to your own computer. You don't mention broadband, satelite, 56K dialup, 33K dialup, 300 baud dialup, etc.
It actually sounds like perhaps you have installed some malware or have some corrupt files. You don't mention what anti-virus and anti-malware utilities you have been using up to the point "gateway" suggested downloading AVG. While I do see that one of the errors you mention indicates you have or had SpamGuard you haven't presented much in the way of specifics. Do tell us.
Have you made use of the Add/Remove programs applet to select Internet Explorer and then select the repair option?
I have a gateway computer that keeps shutting down with error messages that read "iexplore has caused an error in JSCRIPT.DLL"
"iexplore has caused an error in KERNEL32.DLL"
"iexplore has caused an error in SPAMGRD.DLL"
gateway said they thought it was a virus and to download AVG
I started the download and it says estimated time 12 hours. Should it take that long?
Any suggestions on how to fix this problem?