Avast free 4.8 program will not update

I’m using Avast free 4.8 on my IBM laptop and after I upgrade the program through Avast and reboot I lose my desktop (no icons). The only way I can update Avast is by uninstalling Avast in safe mode and reinstall by downloading the latest version. The iAVS update properly. I’m using XP Professional SP3, On line Armour (free) and a free version of Superantispyware. I have tried disabling OA and SASW to no avail. As I said, I can upgrade, but I really would like to know what the problem is. I have never installed another AV program on this laptop.

Thanks

Put online-armor into learning mode, and try a manual update, that has resolved this sort of thing in the past.

Did your laptop come with a trial version of any AV, common practice, if so what ?

I think I have tried OA in learning mode and it did not work, but I’ll try again. However, by disabling it, in effect you are doing the same thing. Actually, I formatted and installed the OS on the laptop and installed Avast right away.

Thanks,