Can't view drives in My Computer

[gailr]

I cannot read from a cd on either my installed cd reader/writer or on my external one.  Neither of these show up as icons in the MY COMPUTER window.  I think that this is my fault.  The last time that I used one of them I checked 'Take no Action' and 'Remember This' in that annoying little box that comes up whenever you insert a cd into the drive.  I'd like to change that setting but can't find where to do it.  I don't even know if this is what the problem is.  I'm wondering if someone can help me before I turn grey.
Thanks!

[Kablam]

firstly take no action and remember this wouldn't cause this kind of problem. secondly check if the devices are still enabled or even recognised by your p.c in the device manager. you can find this by
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Right clicking on my computer - properties
hardware
device manger.

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check to see if your c.d drives are there. if they are disabled or there is an error with them then you will see a red cross or a yellow exclamation mark, if they arn't installed there will be an yellow question mark

[gailr]

Darn...I kinda thought that it wouldn't be that easy.  
In Device Manager:  
1.  My external drive shows but with an exclamation mark beside it.  It is enabled.  I should reinstall it?
2.  My pc disc device doesn't show up at all anywhere.  This is no big deal if I can get the external working again.  I would like to know why this happened though.  

Thanks for your help!

[Kablam]

the exclamation means that it isn't installed properly. try re-installing the device. it could be a hardware fault in which case you may have to get a new c.d drive. check the warrenty.

[gailr]

Thanks so much.  I'll do that.  That's probably it.  But now where did my tower cd go to?  Do you think that it's fried?

[gailr]

Well, a couple of new developments.  I got a message that the drivers were either corrupt or missing.  I took the drivers from another computer and put them in...still nada.  I figured that I might have to get a new external cd drive.  I decided to cleanup my computer and get rid of programs that I really wasn't using.  I wasn't using Nero so I uninstalled it.  Guess what?!  All of my drives (forgot that I also had an external dvd which also wasn't being seen) are now working!  Could it be a flaw in Nero?
I'm now afraid to install it again.