In my brief experience in retail computer tech, I've seen hundreds (maybe thousands) of "tech tips". As you can imagine, some of these have been spectacular, and some not so hip ("Click Here to Begin", anyone?).

Of course, not everybody is using Windows XP. In the past year, I've been paid to diagnose everything from DOS 3 to NT4 to OSX to random Unixes. I'm going to stick with Microsoft juicies for now.

These are some of the best. No, I mean the cream of the crop. No, better yet, these are the ones I've never met anyone in meatspace who knew. Without further ado,

The List

Gimme a real logon! (XP)
Hate that stupid Welcome Screen hiding the Administrator account? Press CTRL+ALT, Delete, Delete. That's holding down Control and Alt, while pressing Delete twice.

UnWelcome Screen (XP).
Locked up on the Welcome Screen? You may have a dialog box awaiting your attention behind it. Press ALT+Tab to display the message.

P.S. Fast User Switching takes loads of RAM. Disable it to free at least 24 megabytes or more.

The Ultimate Shortcut
Use the "Run" dialog a lot? Right click the taskbar on any Active Desktop system, hold your mouse pointer over "Toolbars", and choose Address. You now have an Address bar stacked onto your taskbar.
Not just for URLs, kids! You can type any valid system command in here. Try "notepad C:\bootlog.txt" or (under 9x,) "copy msdos.sys msdos.bak".

Safe, but not too safe (9x)
Can't get the system to boot normally, but need extended system features? Hold the right ALT key while booting to load failsafe core system (VMM.VXD) drivers, plus standard extended drivers. Works for many corrupt motherboard driver installations.

The Secret of SendTo
This one takes a bit of Command Line knowhow to understand fully. When you drag a file onto a shortcut, Windows executes a command line sequence in the background to process the request. For example, if your drop "nasal demons.txt" onto a Notepad shortcut (or executable, for that matter), the command sequence is "notepad "nasal demons.txt"". Simple, really. First the shortcut target, then whatever you dropped onto it.

The icons your see when you right-click a file and hold your mouse over "Send To" are shorcuts stored in "{Windows directory}\Sendto" or {{User's home folder}\Sendto", for Windows 9x and XP, respectively. If you drop a shortcut to Internet Explorer in there, you can open any file in a browser by Sending To. Even better, use your batch scripting skills to do cool things with %1.

Kill that logon dialog! (9x)
Hate that useless logon dialog you have to close out every time you boot? Right-click Network Neighborhood, then click Properties. On the first tab you see, change the Logon Type drop-down box to "Windows Logon". Reboot.
Follow carefully. If you mess this up, I can't help you. When the logon dialog comes up this time, it will look a bit different. Enter a username that is not already in use, but no password. At the confirmation dialog, leave both fields blank. If you did this right, you should never have to close out that dialog again.
Note: Not for systems with multiple user profiles or NT network clients.

Introducing the Kiosk
Ever wish you could open a file in a full-screen browser? Use "iexplore -k {filename}" to load a browser in pure content mode. Great for CD autoruns! Press ALT+F4 to close.

Killing the Digital Media Drag
Losing data several minutes to an hour into your video or audio recordings? Your system may be resizing the swapfile to meet the demands of the large files your are creating. Set a fixed-sized swapfile for smooth live capture. WARNING! This is a good way to break your computer if not done correctly. You had better know how swapfiles work before attempting this. I'm not handholding here.

Shut 'er Down!
Ever bump the power switch by mistake? Windows can do a smooth shutdown for you. Go to Control Panel, then open the Power Options. On the Advanced tab, adjust the drop-down box to a function that suits you. You can shutdown, restart, sleep, hibernate, show the shutdown dialog, or just do nothing when the power button is pressed.

No boot? Try this first.
System won't even give you the time of day?

Unplug the system for an hour. You motherboard has capacitors that may need to discharge. Watch out! If your system makes you do this often, consider replacing the power supply.
Try resetting the CMOS using the CMOS reset jumper. Don't ask me why this would ever fix a no-POST error, but it works. AMD Athlon based systems seem to respond to this more often than Intel rigs.
Reseat everything. This includes your CPU, motherboard power connector, and CMOS battery.