Hi Maurauding,
As you are new to computers, maybe it is good to be warned of a few things.
A lot of seemingly "harmless" downloads can include adware, spyware or, even worse, viruses, trojans and worms. This is especially true of games, screensavers, porn sites and other generally useless stuff--but even what seems like an honest-to-goodness useful program could be infected.
Websites can even be infected.
Some mouse animations may not take much memory, but others certainly can.
The stuff that's most likely to attract your young son are the biggest targets for these things.
You should have
[*]a software or hardware firewall (disable Windows' firewall before running the setup on another) -- some firewalls only monitor inbound packets; some monitor outgoing traffic as well (you definitely want that to prevent malicious programs from "phoning home" or from launching a DOS, denial-of-service, attack against someone else's webserver, or from spreading a worm or virus); some prevent cracker intrusions; some have a "stealth mode" that does not send a "blocked port" message back to people using automated intrusion software, so they won't even know they ever reached your computer at all)
[*]anti-virus software (such as avast) installed on your system that includes "resident scanning" (runs in the background to detect "live" new viruses) and email scanning (that prevents you from opening an email with a virus); this is different from software that
only does scheduled or user-initiated scans of the computer, which only finds a virus
after you get it; "resident scanning" usually also automatically scans anything you download and save before allowing it to be saved, or lets you choose whether to do so or not; of course, "online scanning tools" are also only limited to catching a virus already on your computer, and only when you do a scan; also, some viruses, if they are able to run, prevent anti-virus programs from working at all;
this is why they are best used only for emergencies or as a backup when you are temporarily without software[*]a pop-up blocker; there are ones that come with a toolbar (such as Yahoo's toolbar for Internet Explorer); some are included with your browser (such as the new Microsoft pop-up blocker included with Service Pack 2, an upgrade to Windows XP Home); even some firewalls and spyware include pop-up blockers; the best ones make a noise when a pop-up is blocked so you can view the list of blocked pop-ups and choose to show one, which is useful when a link you click opens in a new window
[*]spyware blockers/scanners; can scan or run in the background or both; detects programs that collect harmless information about you or your computer, collect personal information about you or your computer, log keystrokes, or "phone home"; "adware" programs usually include spyware, too; they will also often detect normal, law-abiding software as "spyware" because programs often have a legitimate need to save and pass on information, especially those requiring registration or tracking of events; the best anti-spyware gives you a list of suspected spyware and lets you choose what to do about it; if you're not sure, do internet searches and ask on bulletin boards like this one to get multiple opinions and experiences
[*]adware blockers/detectors; these detect software that will serve pop-up or pop-under ads in your browser or on your computer; adware often uses spyware to serve its adds[/list]
Of course, some adware is completely harmless, other than being annoying and hogging computer resources, but some is actually malicious code masquerading as legitimate software.
Websites can be infected with bad stuff, too. All lumped together, you can call these annoying, harmful, or downright dangerous programs "malware".
There is some overlap in security software, particularly with firewalls often including pop-up blockers and spyware and adware detection. In fact, a simple reading up about "virus", "trojan" and "worm" will tell you malicious code often overlaps 2 or more of these categories, so to some degree the protections of anti-virus software and firewall software overlap.
Don't fall for the old line about dial-up connections not needing firewalls....of course you do! Sure, someone who's on the internet all day stands a greater chance of infection or intrusion, but what do they say about most car accidents happening only minutes from home? Take heed!
Considering your son's age and vulnerability, I would forbid him from downloading
anything without checking with you. Even if you think you won't understand enough to make a good decision, you will probably understand more after discussing with him and he'll learn more to think before downloading.
I don't have need of the "parental control" software recommended here and never have, but even if you use something like that, that won't prevent viruses and the like. Take advantage of the extra layers of control and information, but don't slack in installing security software and learning more about what your son is doing.
Might I also recommend a good magazine for computer newbies and more experienced users? "Smart Computing in Plain English" is wonderful at explaining even more advanced concepts and security issues to inexperienced users. You can get it online at
http://www.smartcomputing.com