Safe Mode is an important troubleshooting tool for all versions of Windows. Safe Mode starts the system with a minimal complement of drivers and services and no auto-start programs, giving you the opportunity to make configuration changes, delete files, or perform tests that are impossible in normal mode.
I don’t know about you, but I sometimes find it difficult to get Windows started in Safe Mode. The official way, of course, is to press F8 at startup and then choose a Safe Mode option from the startup menu, but timing is critical. Too early and your keystroke doesn’t get noticed. Too late and you miss your window of opportunity and start in normal mode.
The solution? If you’re already running in normal mode, use the System Configuration tool to restart in Safe Mode. In Windows Vista or Server 2008, click Start and type msconfig in the Search box, then click the shortcut that appears at the top of the Start menu. Click the Boot tab and select the check box next to Safe Boot, as shown here. (If you have a multi-boot system, be sure to select the correct entry from the list in the top window.)
You don’t need to make any other changes. Just click OK and then restart when prompted. The next time you start, you’ll go straight to Safe Mode.
In XP or Server 2003, the procedure is slightly different. Click Start, Run, type msconfig in the Run box, and press Enter. In the System Configuration Utility window, click the BOOT.INI tab and select the /SAFEBOOT option.
In all cases, after you’re done working in Safe Mode, open the System Configuration utility again, click the General tab, choose Normal Startup, and click OK. When you restart, you’ll be back in business.
Ed Bott 
an even faster way than using msconfig in Vista/2008 is by utilizing the bcdedit command directly.
for normal safe mode:
bcdedit /set safeboot minimal
for safe mode with networking:
bcdedit /set safeboot network
Hi, Ed.
I do NOT recommend using msconfig to boot to Safe Mode.
As you are illustrating in the instructions, this process edits the boot.ini. With certain “rogue” (i.e., an Antispyware 2008 XP infection) and other trojans altering safe mode , if the user attempts safe mode via msconfig, they end up in a continuous reboot loop, unable to get back to normal mode. The “normal” user has no idea how to circumvent that and ends up either with a rather ugly door stop or a hefty bill at the local tech shop.
http://www.malwareremoval.com/tutorials/safemodeboot.php
Corinne, there is no boot.ini in Vista. It is an XP-only file. With Vista, this setting goes in the BCD store.
The point is folks with XP can end up in a reboot loop using msconfig.
Even the most ignorant of my users can get into Safe Mode using F8. I’ve never had an issue with them using that. If I tried to explain msconfig…..even I even showed them using msconfig (I’d also have to explain how to login as administrator or runas) then they would more than likely click on something else in there.
Stick with F8. It’s simple.
It’s been a while since I needed safe mode without windows telling me I did (mostly because we’ve locked down our user’s PCs so they can’t install anything, and have images for all the computers!), but back in 98 when you needed safe mode every few days, holding down the CTRL key during POST would achieve the same thing; Additionally, wouldn’t cause the quixotic message “Keyboard is stuck or not present, press F1 to continue”. Can’t tell you if that still works, but certainly did in 98.
Actually, Keith, the old Ctrl-key-at-boot trick did something slightly different. It booted in Normal mode but didn’t load any startup programs. The difference is drivers. Safe Mode loads a minimal and generic set of drivers for things like video adapters, allowing you to recover if a driver is causing problems.