I have 3 systems with the same problem.
When I try to update the program or anti-spyware manually, I get the following error:

Error: download error

A clean un-install and reinstall has not fixed this. (one system only)
The only changes to the 3 systems are security updates. They were all working fine yesterday.

All 3 systems have the following:
ZA Pro
XP Pro with all the windows updates
Each has a different AV (AVG, Avast, and Avira)
Any one have any ideas as to how I may fix this please?
Thank you.