Its truly funny reading some of the answers that you've received.
To the intelligent people who are offended when asked if they have rebooted their computer, or have been asked to turn it off and back on again, or other similarly obvious questions, I say to you: For every person who thinks that's an obvious question that didn't need to be asked, there are 50 people who never thought to try that. I once had a customer pay me for two hours of my time to drive 60 miles round trip to TURN HER COMPUTER OFF because she wasn't comfortable doing it herself. And then returning the next day to turn it back on for her. I have visited customers who very indignantly assured me on the phone that their computer was plugged in and that THAT wasn't the problem, only to discover upon my arrival that their computer wasn't plugged in, and it was indeed the problem.
But to answer the question at hand. Years ago, before I owned my own computer consulting business, when CD burners were first coming onto the market, I bought a Philips CD Burner for nearly $400. Generally, I discovered that when it worked, it made more coasters than actual burned CDs. But at that time, that was pretty typical of the early burners. Unfortunately, this burner had other problems. Its drivers weren't fully compatible with Windows.
I could turn the computer on, and the CD burner wouldn't work. If I uninstalled the drivers and reinstalled them -- a process that took about 30 minutes at the time -- I could use the burner, reboot the computer, turn the computer off leave it off for up to 3 hours and turn it back on, and the burner would continue to function. But if I turned the computer off and left it off overnight, then the burner wouldn't work in the morning without having to reinstall the drivers. Clearly something on the hardware maintained a charge of at least 3 hours so even a cold boot was somehow a warm boot.
I called Philips technical support, several times. In the end, their advice to me was to leave the computer on and never turn it off.
While there are lots of reasons to leave computers on and not turn them off, none of those reasons have anything to do with the fact that the computer won't work without reinstalling the software when you turn it back on. The idea that their best answer was to just leave the computer on so I didn't have to reinstall the drivers was clearly a tribute to the fact that they didn't have a clue or they did and didn't want to have to fix it.