Cannot install programs on win 2003 standard server

Just upgraded my server to 2003. All has gone well but I'm having trouble

insstalling programs.

Two examples are pcanyware (11.5) and AVG file server edition.

AVG gets as far as asking what version you want installing, there is a pop

up window that appears for about half a second (don't know what it says as

there isn't time to read it) and then nothing happens.

PCanywhere starts installation then rolls back saying that setup was

interuppted.

I've enabled active content from cds and tried turning off the web Internet

Explorer Enhanced Security Configuration (first off completely then just off

for the administrator group) but this just stopped ie browsing all together,

just in case this was the issue.

Has anyone got any ideas how to overcome this?

Thanks

Tom