What is so magical about a re-boot?

Attempting to Skype with my daughter, and she can’t hear me. I do a Skype test call, and they can’t hear me. I download the latest and greatest Skype update. Nada.

I reboot and all is good.

So, what is so magical about a reboot?

One possible way to stabilize things in Windows is go to control panel , sound,

and for both of playback and record, disable any entry that isn’t going to be used.

Also note that the recording device may be through the mixer, which you can see here at the record section and the reboot might set it back to microphone…

At boot, the computer’s volatile memory is set to some known initial state. The operating system is then loaded to memory from disk.

Operating systems are imperfect and though this is not supposed to happen, it’s possible some OS function in memory has been accidentally overwritten, or otherwise made non functional. Rebooting the system puts everything back where it belongs. If the system call that Skype uses is the one that got corrupted, then Skype won’t work right until you reboot. Typically you don’t use the microphone so you might not otherwise notice a problem with it, as everything else is still working fine.

Mostly because computer software is sufficiently complex that they always have ways of backing themselves into a corner. Whereas you might, if you had time, be able to craft a system that didn’t have silly cases where the exact order of doing things mattered, there is never the time. Or indeed the systems are sufficiently complex that the sun might go cold before you found and fixed them. (Complexity is exponential with the amount of stuff in there.) Failures are often rather like locking your keys in your car. If you had done things in a different order you would be fine.

A reboot is essentially taking your car apart into its components, including the keys, and putting it back together again. Most times the keys are outside of the car when you are done, so you are good to go. Sound on computers often involves a set of competing bits of software trying to control the sound, and getting to the point where none of them are able to get out of one another’s way. In the worst situations it becomes deadlocked (which in computing has a very precise technical definition.)

Nice explanation. Thank you everyone.

One other advantage of rebooting which might apply in your particular scenario (where you tried to update Skype) is that some processes can’t happen while Windows is running, and will only run while Windows is shutting down/starting up. You may have seen Windows updates that say you need to restart to finish, or driver updates, program installs, etc. This is often because there are files in-use while Windows is running that can’t be deleted or modified. Or services that have to be stopped, but Windows can’t function if you stop that service. And so on.

In some cases rebooting can also fix a memory leak.

Well, more because Windows is a kluge. Programs may crash, but they shouldn’t lock up the OS. I had my Sun workstation for about 8 years and I might have rebooted it twice. You could add patches without rebooting. I read somewhere, the Register I think, about a BSD server which has been up for 18 years without a reboot. And I use a Solaris compute server which only goes down when they turn off the power in the computer center once a year for electrical work.
So reboots in general are not necessary - when you have a real OS, that is.

Reboots in general come from flaky hardware and software. They used to be confined to computers, but I learned differently when our TV didn’t work in a hotel and the maintenance guy came to reboot it. The first thing you do if your DVR get s flaky is reboot it.
I wrote a column about reboots. While working on it I asked a bunch of people about their experience. One woman said her digital picture frame had to be rebooted often.
Trust me, you’ll be rebooting your refrigerator and your toaster before you know it. My coffee maker/grinder has an Intel Inside sticker on it, but so far I haven’t had to reboot it. So far.

[/ol]There are 2 parts of a reboot where problems can be fixed.

In the process of shutting down (the “re” part of a reboot), the computer basically tells all the programs* as well as actual programs) “wrap everything up, clean up your area, it’s time to go home”. If your problem was caused by some program not releasing a resource skype needs to capture, encode, and transmit sound (from your mic or whatever) this will make that program release those resources.

In the process of booting up, a computer :
[li]completely rediscovers it’s physical self (this is how hardware changes are detected)[/li][li] builds up it’s virtual self (where stuff is supposed to be and what it is) to a fresh state, which every program is familiar with and understands. Picture the difference between a workshop that’s just been cleaned and stocked, where all the tools and supplies are in their designated spaces, and an active workshop, where tools may be lying somewhere on the shop floor, or even in active use by somebody else. [/li][li] Finalizes any installations that change certain parts of the system (e.g. system updates)[/li][li] Does all the stuff you (or, more often, the programs you’ve installed) have told it to do on startup. This is the part takes more and more time the longer you own a computer. [/li][/ol]
*by “programs” I mean services, background processes, scheduled triggered tasks (e.g. disk defrag, memory cleanup) and the like, as well as actual programs

Not surprisingly, a lot of DVRs are built on Windows. Mine are running WinCE, so it’s not too surprising that they get lost now and then, and even when they don’t act goofy, a monthly power cycle helps keep things running smoothly.

QFT. I once did, deliberately or not, quite a lot of “stress testing” of Unix systems. Processes have no unintended effects on each other. Even “denial of service” attacks are difficult. Kernel panics were as rare as four-leaf clovers and attracted much interest.

Windo$e is opposite. I’ve learned to start the Cygwin X-server only when no other task is initializing; otherwise I often get a flawed environment. :smack:

As noted, it isn’t just software running under Windows that can be fixed by a simple reboot. I work in industrial IT and I routinely fix a comical number of things ranging from industrial controllers running equipment the size of a house to core networking switches that control everything in multiple buildings. I don’t like it when that happens because it makes my job seem much easier than it really is to casual observers. As an engineer once explained to Henry Ford after diagnosing a problem, ‘You aren’t paying me to simply walk in and draw an X, you are paying me because I know exactly where to draw it’. Some complex industrial equipment has hundreds of switches and complicated reboot procedures.

The reboots often work for the reasons given above but that doesn’t mean that anyone can just turn things off on willy-nilly without serious problems on some equipment. I am sure that airliners have reboot procedures for their critical electronic equipment as well but you don’t want to do that unless you really know what you are doing. If it is your own computer though, feel free - it can fix a whole lot of problems.

Even Android benefits from the occasional reboot, as I’ve found out with two different makes/models of smartphone.

Me too.