Adding links right now. I'll also add AbiWord (a compact word processor) and SciTE (a compact text/source editor). Keep them coming, but try to limit yourself to stuff that you actually use or have used.

I just recently started using Auslogics Defragger to defragment my hdd. Their website is a little difficult to navigate to the free software, but it's there, and I use the free version.

I'll add that later, along with ProcExp, Avira Antivir, Junction and especially Locate32. Wouldn't know what to do without that one. My files have meaningful names and a fuzzy search like Google Desktop only turns up false positives for me and besides, I hate indexing tools running in the background.

PrintKey 2000, a handy screen capture utility that works with Win95 through WinXP. (There's PrintKeyPro now that works with VIsta, but it's only a free trial, not true freeware.) Install PrintKey2000, set to run at system startup, and pressing the "PrintScreen" button will bring up PrintKey while in any program.
Absolutely priceless for those moments when tech support asks you to describe the problem. "See?" :) Also, I have a couple of games that don't minimize with Alt-Tab the way they should; I've found that using the PrintScreen button to call up PrintKey in the middle of the game will then allow me to minimize them (no idea why this works on my machine, but it does).

escapedturkey, please use the hyperlink button when you're posting URLs. It's the little chain icon just to the right of the one for underlined text. The URL goes after the equals sign in the first tag, and between the tags you put the text to actually be displayed. Both can be the same, if you like.

Avast - virus protection free for non-commercial home use. Requires you to register online once per year to receive a serial key, but there's no charge for doing so. Frequently updated and includes active scanning. I've been using this for a few years now and have had great results with it.

Exult is a program specifically designed to run Ultima 7 and all add-ons/expansions on modern day systems. The program also introduces a variety of improvements to the original game. Best of all, the whole thing is free.

I think Exult should rather go into the games thread, as it is more of a free addon than a standalone application. Anyway, guests tonight, so I probably won't get around to update the first post until tomorrow, but it will be updated!

That, and the fact that it's enitrely possible that said noob would skip through the warnings that installing a new OS could potentially erase all his files, and void his warranty on his HP, are reasons why I don't recommend linux use without supervision.
It's not terribly difficult for most people to get into, but if you were to look at some of those Xbox 360 players who play madden, and halo and etc, who have computers that they use to share their myspace photos on for the majority, ending up somehow to this page, when doing a google search for good games, they'd probably be to utterly confused..
anyway, my point is, with installing something like the gimp, tugzip, or firefox, you don't run the risk of deleting your hdd

On the other hand, you might end up with a situation like this. :-D

*shudders
I do computer work for a living, and when I come home, I don't typically want to fiddle with my own computer. Linux doesn't take a lot of fiddling once you get it started, but typically the OS I stick with is windows because I don't want to have to fiddle even more for each of my games.
For valve source games from steam, I already have to tack on -threads 4 -heapsize fifty billion.
I come home and just want my pc games to work (this is partially why I play console games as well). With Linux, or Mac, it's entirely possible to get the games working, and even better than they do with windows. I've used Cedega to run Steam and I've actually gotten a better FPS than through windows natively, however I'm not willing to make that initial investment to get everything working the first time through linux or OS x.
I'm fine with windows, and for most users, who get windows on their computer, it's better for them to continue to use it, rather than to learn how to reinvent the wheel all over again.
No, grandma does not need to learn how to use linux, windows 98 is fine.
It's all based on "what do you need to do?" and "what are you comfortable doing to get there?" as opposed to system resources, stability, or other features..
If your main interest in the internet is to browse webpages and do email, you don't need to switch to linux, even though you can do the same things. if you want to, you can, because linux can do those things just as easily. If you're looking to write code and compile programs, you're probably better off running linux, although you can do the same thing under windows if you really wanted to.
this is where we are today, where it's more a matter of aesthetic opinion over actual functionality, because you typically can do everthing one operating system can do, just with a little bit of extra work.
edit:
really a minus one? are your that much of a linux fanboy? seriously, I was making an objective post. Windows Vista isn't necessary for some people even.. if someone wants to upgrade their computer by changing their os or adding hardware components, I usually advise against it. There are things they can do to improve the computer they have now. And at the same time they don't have to change much of their habits..
Elderly people typically don't have the patience to learn something new, switching operating systems or spending extra cash to just browse the web the same way they did a few months ago..

Yep, never, ever let somebody do a linux install on his own... on the other hand, I gave my mother SUSE 9 a while back (I set it up) and she was perfectly happy. I mean, I became a nervous wreck, but she was happy ;) Finally bought her a Mac instead. Not the perfect OS for me, but it's a heck of a lot easier support than either Linux or Windows.
To be fair: There were a lot less issues when she had Linux running than with Windows. The only real thing missing for her was a good help file (she's nearly 60, I can't just send her off to linuxquestions)... and that's where MacOS really shines. When I set it up, I went through dozens of forums looking for some answers, assuming that the help would be as helpful as its Windows (too little information, and always in the wrong place) or Linux (Help -> use --help -> use man -> use info -> find out that the service you're having problems with is actually provided by something else, repeat) counterparts. But the MaxOS X help is really helpful.

Irfan view is a great image, avi viewer. I haven't been using it as of late, as I've been using the Zune player mostly for my videos, because I of course have a zune, and windows image and fax viewer is fantastic for XP, but for Vista or win2k or older, Irfan view is a really great way to go. Although it doesn't scale images to your screen size automatically, you might be able to change that setting.
Why use the zune player? well, typically the only real reason to use it, is to sync a zune, or if you have Xbox Live, you can link your gamertag to it and show other people what songs you listen to.
Also the Microsoft points you buy in Xbox Live, can be put towards songs in the Zune Marketplace.
In the future, expect more communication between Xbox 360 and Zune, Microsoft has been hiring for someone to set that up.
edit:
also another interesting feature of the zune, virtually any .wmv or mpg video will be automatically scaled to the zune screen and synced to your zune.
not really information for people wanting freebies, but it's about the only pro over an ipod that I've found.

Space Moger is an awsome thing to use. It helped me to lose about 10 GB of stuff I forgot was even on my own harddrive. Very useful for old computers that have alot of clutter.

plus if you have some games installed on your hdd, just because, it'll let you know how much space that's actually taking up, to give you a better idea as to whether or not you'd like to uninstall it.
it also helps me to remember to empty my trashbin, it usually gets filled with videos I've recorded that I don't need anymore.