My computer has crashed a couple of times and the screen says something about disabling shadowing and caching bios. How can I do this? Should I do this?
When you boot up, depending on the make of the computer, you need to enter your CMOS setup by pressing DELETE or a function key like F2 or F8 or something like that. You’ll have to rummage thru the different areas of setting until you find the one that contains the info you need to turn off.
Please do be careful not to mess with any other settings in the BIOS.
How old is your computer? I suppose there’s a chance you need a new CMOS battery if it’s more than a year old, although those they’ve been using in the last ten years have been much more durable. Still worth checking, if your BIOS fix doesn’t stay fixed.
It is also possible that you will need to contact the manufacturer to get a replacement/new/upgraded BIOS downloaded into the EPROM.
Just don’t get freaked by all the alphabet soup. 
So long as you go through it all slowly and carefully, being sure to change nothing except what you’re told to, it should go alright.
Also, please get a notepad and write down each change you make, Just In Case. Trust me, you’ll never regret precautions of this sort.
How do I even get to where I can chnage BIOS settings? I can get to a menu by hitting F8 during start up but what do I do from there?
It doesn’t look like anyone else who has worked with this stuff more recently has volunteered. I’ll try to walk you through, but you’re going to have to write down each of the choices on the F8 menu and tell me what they are. I can then tell you which of those to choose. And, if we’re lucky, it will jog my memory as to what the contents of the next menu are likely to be. <hope, hope>
The “no worries” part of all this is that you can always <esc> out of the menu, no matter how many levels in you are. So don’t worry that something will get messed up, so long as you’re not changing anything. 
It’s been at least 5 years since I had to mess with a BIOS (practically an eternity in computer terms). And the last time I had to fix a problem of the sort yours seems to be is several more years ago.
So just gimme the menu, okay? 
And I’ll try and logon in the middle of the day, so we can maybe cut down the lag time.
On second thought, select the first item on the menu, and write down what the second screen says. Then <esc> back to the first menu, and do the same for each of the choices. Too bad there’s no earthly way to do screenshots 
(except by the BIOS/CMOS mfr; you don’t have a manual for that, perchance?).
On most computers, there is some magic key or combination of keys that you have to press to get into the BIOS. Usually it will say what this magic key or combination of keys is while the computer is booting, but sometimes all you will see is a splash screen (the screen with the logo, may have a progress bar at the bottom). On my computer it’s F2. Usually it’s either F1, F2, or DEL, but there are others (CTRL-ALT-ESC being one of the most cumbersome I’ve seen).
Once you get into the BIOS, there are usually several screens. The first one is usually just where you tell it what type of hard drive you have (usually set to autodetect) and if you have floppy drives, and that sort of thing. Usually the screen after this (often called something like advanced settings) will have the type of settings you want. It usually also has things like the boot sequence (floppy or CD first, etc) and whether or not the num-lock key is turned on by default. There will usually be an option to shadow the main BIOS and the video BIOS.
The main reason you want to shadow the BIOS is that they are EPROM chips, which are much slower than RAM chips. Shadowing copies what’s in the BIOS to RAM mapped to the same memory area. Any BIOS accesses are then really just RAM accesses, which speeds things up a bit. The fact that your computer wants you to disable them kinda hints at a hardware problem, possibly faulty RAM. You might want to try taking your RAM out and re-installing it to make sure it is seated well. You might want to do the same thing with your CPU. I doubt that simply turning off the shadowing is going to help much, though it might make your computer crash in a different place.
Windows has its own startup menu independent of the BIOS. To get to this one, press F8 after the BIOS has finished booting. Most of the time a BIOS won’t use F8, so I suspect you are getting into the windows setup, not the BIOS setup. The BIOS is what starts up the computer. When it is finished doing things like checking memory and assigning PCI resources and such, it tries to find an operating system and if it does, it boots it. Once you get to the F8 menu, windows is already starting and the BIOS has already long since finished doing it’s stuff. You need to stop it way before then.
:smack: AAaaaaarrrggh!
I knew there was some reason why F8 didn’t sound quite right. ISTR some that used the “soft boot” to access the BIOS, but don’t recall encountering it in the last 10 years, maybe more. I’m pretty sure I’ve also seen machines that used <esc>, so the main thing to do, starting as soon as you hear the beep and the keyboard lights blink (POST - since somebody will probably ask “what’s that?” I’ll just say now that it stands for Power On Self Test) is start trying the keys that engineer_comp_geek suggested, with the possible addition of <esc>. I’d start with the <del> key, as I feel it’s the most promising, then try F1, F2 and then <esc>. I have that nagging feeling that I’ve also encountered F4 being used this way. Problem is, I worked on so many different brands over the years that it all tends to run together now.
One other thing I didn’t think about until after I’d gone offline. I have two questions:
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Is this a name brand PC or a “white box” (assembled by some local company)?
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If it’s a name brand, have you tried contacting the manufacturer?
You can probably get some trouble-shooting help even if it’s several years old. I was able to get some support from Compaq (now HP) last year, and I bought that machine in 1999. Companies vary in how long they’ll give support, but it’s worth a try. At very least they should have a manual or FAQ or something online. You might be asked to pay for phone support, but web and email support seems to be growing ever more popular, as manufacturers become more aware of how much importance customers attach to support.
If you try the above (having ascertained that you can’t get support from the manufacturer), then please do have a writing pad and pen/whatever, and write down everything you do, and what results you get, to tell us about it. I think that now you have engineer_comp_geek’s explanation, you see that we need to know what it tells you. Once you are able to see the BIOS load, you should also see the copyright notice, which will tell you whose BIOS is in your PC. Please include that in your what’s next? report, unless you’re able to get help from the PC manufacturer.
There was a time when (except for IBM, which provided massive support for their early PCs - that’s one reason why they were so expensive; other manufacturers were much less helpful) you couldn’t get the “time of day” from the manufacturer, once the factory warranty expired, and that’s an important reason why the culture of computer people developed as it did, with all the “peer” support. The massive indifference that everyone faced at some time or another made (most of) us realize that the only help we could really count on was from other individuals. And it doesn’t take enormous intellect to realize that you’re likely to need the help of others, sooner or later, and that if you’ve been unhelpful, you may find it harder to get the help you’ll eventually need.
First, replace the battery on your motherboard, just to be sure (probably a 2032, $3 at Wal-Mart). Next, lean on ANY key, reset the computer or apply power to it. The BIOS will eventually detect the key as a stuck key and offer you some options, one of which is to enter the BIOS info. (F8 is a Windows convention and may not be a BIOS one.) There should be an option to reset everything to default. Try that first. Save & exit. Let it boot normally. Should work for starters – it does for me, all computers.
Afterwards, you can experiment with tweaking some settings like caching. One thing at a time. If it doesn’t work, revert.