Leaving the power on and whether or not a program will lock up are two different things.
I am running the Firefox Browser Nightly Beta (not well tested). It will quit running and sometimes BSOD (hang my Computer) once every few days. I run it under WinDbg (a Debugger) so that when the Program has a problem I can write a Bug Report for Mozilla (the Creators of the Program). Hopefully someone will fix the problem and then when this version is released to the general public it will work better for them.
The "stability" of your Computer should not be affected by leaving it on, it could be, but it should not be
. If you have a borderline Part or insufficient cooling it can cause something to overheat and fail which will crash your Computer, as will running software that is not well tested.
There are many Companies that make it their business to have their Computers run Programs for as long as possible (power on and no crashes). You have heard from a few of us that we always
leave the power on - that does not mean that there is never any problem, only that the "power is on" (which is what you asked).
The people running this Forum likely "leave the power on" all the time, how else would it work?
- Did you build your own Computer or add new Parts ?
- Are you overclocking ?
- Is it particularly hot where you are ?
- Are the Programs that are running on your Computer all very well tested ?
- Is your Computer a 'quality' or 'value' System ?
Often just one thing can be the source of your troubles, if it is a few things then that is more difficult to fix.
We can help you try to find the source of the problem and hopefully your Computer will be able to remain on and working correctly
for long periods of time.