I used to work first level HP Pavilion tech support a couple of years back, so here's what you'll need to do. First off, as soon as you turn on the computer, just start tapping F8 about 2 times a second. This way, hopefully you'll hit the right time when it should be hit, and the menu will pop up for you to go into safe mode. If Windows starts loading, obviously it didn't work. Try this a few times just in case you didn't catch it the first time. The second option is holding down the Ctrl button when booting the system. Now this may or may not work, but power on the system, then hold down the CTRL key until the menu (hopefully) shows. This always seemed to work just sometimes in the year and a half when I worked at HP, but of course I worked with all the simpletons who would buy a computer from Best Buy and not know what a mouse is, so they could've been doing it wrong for it not to work. Also, I'm not sure if holding the CTRL button is a feature on all comps or just HP's, so good luck with it.
Try those things, and get back with me.
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