There are a handful of ways to (hopefully) capture videos from the web. Downloaded web vids are usually in FLV (sometimes MP4) format, which most players can't play. Converting them is covered near the bottom of the page.
Temporary Internet Files Folder
In most cases, like YouTube, they'll end up in 'Temp Int Files' when using IE. If Firefox has one major failing, it's that it doesn't allow you to access the cached files like IE does. If there's an add-on that does it, someone please let me know.
Using IE, go to the Tools menu, 'Internet options', click on 'Delete', leave the top two boxes checked and click 'Delete'. That should flush out most of the 'Temp Int Files' folder so you can single your file out more easily.
Go to the web page, play the video. Hopefully, it'll have a download gauge so you can tell when it's fully downloaded. If it doesn't keep reading ahead when paused, you'll have to play the whole thing through untouched.
Open the Tools menu, 'Internet options', click the top 'Settings' button, then 'View files'. A folder will pop open. The first time through, go to the folder's View menu, select 'Details'. Click on the 'Size' at the top of the folder twice to bring the largest files to the top. If it downloaded to the cache, it'll be there. Copy it to a different location and there ya go.
The Temp Folder
If it's not in 'Temp Int Files', it might be in the 'Temp' folder. Go to the page in IE and play the video. These types usually don't read ahead when paused so play the whole thing uninterrupted. Leave the browser open when it's finished.
Open the 'Windows' folder on the C Drive, then the 'Temp' folder. Again, view it by 'Details' and sort it by size, or perhaps 'Date modified' to see the most recent entries. If it's there, it'll probably be huge in size compared to everything else.
The problem here is, the file is 'in use' and can't be copied to somewhere safe, and the instant you close the browser window, it's deleted.
The answer is to take a deep breath and pull the power plug.
You can test your tower and see if its power button will do the trick, but the power button in most newer towers acts more like a 'forced reset' function and Windows will close down the browser on its way out and the file will be history.
Windows will, of course, be seriously pissed because of your heinous act, and if it goes to the 'Safe Mode' page upon reboot, do it, and wait for the HD light to go out after Safe Mode is up. Then reboot to your normal system. I tried a straight reboot the first two times and the first time it got hung up loading Task Manager and the second time had nothing but a black screen. On the other hand, actually pulling the plug on the rascal is a rather dirty trick, so it's understandable if Windows gets a little miffed. You'd be miffed, too.
If it's not in 'Temp Int Files' and not in the 'Temp' folder, there's one more thing to try without resorting to outside software. First, go to the video page with IE but don't watch it yet. Now go to the page with Firefox and play the video uninterrupted. Now go back to the IE page and play the video uninterrupted. I know it sounds crazy, but a few minutes after IE is finished, the files (one for each browser) might appear in the 'Temp' folder. I've seen this happen a couple of times, with the files, strangely enough, not appearing for a minute or two later. Also, 'Refresh' the window occasionally as, being a system folder, it might not auto-refresh as it should.
Online Grabbers
Another way to grab videos is with a site like KeepVid, where you enter the address of the video page and it grabs it for you, but I've never found them work very well. Also, if the video is in multiple parts, like if it has a quick commercial intro, it'll only grab the first part.
FreeCorder
For add-on software, try FreeCorder. After the Republican 'family values' forum the other day, I wanted the video to grab some clips. There was a crappy version on YouTube, which would have dumped nicely into 'Temp Int Files', but I wanted the better quality video on the home site, which didn't use either 'Temp Int Files' or the 'Temp' folder. I first tried KeepVid (didn't work), then hunted around for an external downloader, someone raved about FreeCorder in some forum and it did the trick.
The bad news is that it doesn't work with Firefox 8 (more specifically, it hasn't been updated yet), and since it works fine in IE, that's good enough.
The other bad news is that it puts this big tool bar across the top of IE, but it's easy enough to disable by right-clicking on a blank area of the tool bar and selecting or un-selecting the program. In both cases a small box will pop open. Just click 'Enable' or 'Disable'. If it doesn't display the first time you enable it, go to the menu and select it again. The first time just enables the program and the second time actually displays it.
Setup
Open the browser, click on the little wrench icon, 'Settings'. Select a download folder, then kick the 'Audio Bit Rate' up to '160'.
Usage
Just go to the video page and click the first small button, 'Video History Tool'. If it finds the video, it'll start downloading it. If it lists it but doesn't start auto-downloading, close the box, start the video and re-open the box. When it's finished, click the 'Save Media' button over to the right of the box, then 'Save as Video' and you're done.
It doesn't have a 'Minimize' gadget, so if you want to get rid of it, either click the blue gadget on the very top-right corner of Windows 7 or, better, open Task Manager, first panel, right-click 'Freecorder' and select "Minimize'.
Bug Report
For some odd reason, the tool bar is nonexistent when you go to a site via a shortcut icon, nor is there even an entry for it in the tool bar menu. You have to first go to the site, click in the address bar to fully highlight it, hit Ctrl-C to copy it to memory, open a fresh IE and paste it into the address bar with Ctrl-V.
Converting Downloads
FLV is a nasty, finicky, highly proprietary Adobe Flash format and not many players play them and not many converters convert them.
The download will mostly be in FLV format and will probably need you to stick an ".flv" file extension on it. If you want to convert it to a friendlier format, like AVI, try this page. If it's an MP4 file, try playing it with whatever players you have installed. On the rare occasion you run into a WMV, it should play fine with everything.
Other Video Notes
I'll include some general video notes in case anyone's interested.
— My massive, if slightly outdated, video how-to site is here. Over 650 pages, 1,000 pics for the guides. For a while, about ten years ago, from the two years before DVD burners hit the scene to a few years after, it was one of the most popular video sites on the web. These days, with so many smart, do-all video programs around, much of it is outdated, but I've left it un-updated in case anyone wants to make a DVD the old fashioned way, or convert some video in some bizarre format that regular programs can't handle. VOB and TS spring to mind, and half the players and converters haven't a clue what MKV is, and very few load WMV due to Microsoft's outrageous licensing fees, and even more so with FLV and Adobe.
— Speaking of do-all programs, my pick of the litter is ULead's VideoStudio, and I have a whole site wrapped around it here. I primarily use it when making clips for my Bag O' Clips because I like the snazzy transitions. I output VideoStudio to AVI/Huffyuv format, then make the actual WMV in MSoft's Media Encoder 9, because my tests have shown it's the best. Which makes sense, being that it's a Microsoft product making a proprietary Microsoft file (WMV), the same way Adobe's Flash 8 makes the best Flash (FLV) files. It strikes me that they're saving the best encoding algorithm for themselves and leasing out a slightly inferior version.
If you're wondering why I output the Bag O' Clips to WMV rather than FLV, it's because I'm going for the highest quality and, bitrate for bitrate, WMV has the clear edge. This means the Mac users can't see them without some special plugin, but such is the price of glory.
For regular web vids, I use VirtualDub to get everything into AVI/Huffyuv format, then convert it to FLV with Flash 8.
— One thing I've recently started doing is making sure every off-the-cuff render, like a web vid, has a width and height divisible by 16, rather than 8, when dealing with FLVs. It came about when putting together my Google Earth Project, and I noticed a bar of blurriness running across the bottom, about 10 pixels high. I first tried just cropping it, which worked, but then I thought of trying 16 instead of 8 and that took care of the problem.
First, a little background. All files you see and hear via your browser are downloaded to your computer first. You may think you're reading a web page on some server in New Englandtown, but you're actually reading a file on your computer, and any pics, videos and music you see or hear are also being read from your computer.