you can do it one of two ways....start menu or run menu. You choose.
Step2
Either way, type: msconfig
Step3
It will open the system configuration
Step4
Click the selective start up (you don't have to do this part) and choose what you'd like to have in your safe boot...such as your start up items. If your computer needs safe boot really bad, you can choose 'Diagnostic startup' located above the selective start up area.
Step5
Go to the Boot menu, then once it opens, click 'Safe boot'. Here you should click if you'd like Networking (Internet) or not and other things as well. To have the least running when you run in safe mode, just click 'minimal' (or leave as is)
Step6
Once done, click 'Ok'
Step7
It will ask you if you'd like to restart now, or close without restart. You choose.
Step8
Once it starts up, and you've done what you needed, go back through the steps again and this time, instead of clicking 'Safe Boot', click 'Normal', like it was when you started.
Step9
Click 'Ok'.
Step10
It will ask again, if you'd like to restart now, or close without restart. Restart.
Tips & Warnings
you may, at your own risk, choose what you'd like in the safe boot to be ran or not ran, in the extra boxes, which are included in the system configuration window. You can see them in the same area as the 'Safe Boot'.
make sure to turn the computer back to 'Normal' once done, or you'll be starting, once again, in 'Safe Boot'
unless you decided to, you will not have Internet (network) access while in 'Safe Boot' (mode) (step 5)
If you're doing this because of a virus/worm/trojan, I strongly recommend turning OFF the System Restore BEFORE restarting into 'Safe Boot' (mode). (my link below)