>>>"When you speak of the boot sequence I take it you mean the sequence that's part of the System Restore process"
Er, no!
Restart your PC and while it's 'getting itself ready' (before you get to the Windows screen) press F8 . That's not the same as going into the BIOS (which, possibly understandably, worries some people). It simple starts Windows in its most basic form. (So none of the programs which normally load when you start your PC will be running and unnecessary drivers, such as those for your printer and video card, won't be loaded). Unlike entering the BIOS, it's 100% safe. You definitely can't damage your PC by using Safe Mode!