mcafee virusscan update problems

i'm new to this forum and my dell dimension (w/windows xp) is new to me. it arrived in january with "dell security center" already loaded. via security center, i downloaded/installed a "free 90-day trial" of mcafee virusscan online, privacy service, and firewall plus. since then, i frequently see a popup window telling me virusscan updates are available/do i want to update? when i say yes, i'm taken to a screen that says the update should happen automatically/but if not, click Update. i click Update, hear a zzzzt sound, but nothing happens. i've been talking to mcafee tech support for a couple of weeks, but nothing they've suggested has resolved the problem. one of the steps i've tried, at mcafee's suggestion, is to uninstall virusscan, then reinstall directly via the mcafee downloads site. when i did that, got the same zzzzt/then nothing that happens when i try to update. however, was able to reinstall via the "dell security center" moments later without difficulty.

i'm told the version of virusscan i have is outdated (build 4.4.35, engine 4.2.60, DAT version 4.0.4271, DAT file created 06/23/2003).

when i called dell tech support they advised me not to bother with updates, that it would mess up my system, that if i have a relatively current version virusscan running that's enough and i should just stick with that. how can that be? why would mcafee be coming out with updates every day or two if it is unsafe for users to install them?

anyone out there who can shed light? should i just forget about mcafee and get norton? i know next to nothing about all this stuff.