This can be almost impossible especially if the cover has never been removed. The directions don't help much since they say "if" your computer has a latch. Make sure you are sliding the latch button to the right, not just pushing it. At least that what the manual shows. Look for subtle arrow imprints on the case and possibly another release button. Don't over do the pressure which can be counterproductive <ADMIN NOTE: Broken link has been removed from this post by Dell>

There's an indentatation at the back of the sliding cover; pinch two fingers against that and pull while pushing the release latch toward the bottom of the chassis. You might also try wiggling the sliding cover as you pull.

Also, I hope Dell has rectified this issue in their newer models.. it's kind of ridiculous

Yeah... it still won't budge. Any ideas for non-conventional methods I could use to get it off that don't involve power tools? Basically it won't work unless I can get it open and clean it.. so if I can't get it open, I'll just have to throw it away..

I've never used a B110, but I've never had issues with any of the other dozens of different models I've worked with - when the case hadn't been damaged.

I'm assuming you have checked for possible retaining screws ... I remember one old system that had an almost hidden screw securing the cover.

Try a screw driver to pry it?  I used that once on a case that had been dropped, and the retaining rail for the cover had been bent, sort of "locking" the cover into place.  A screwdriver is not a "power" tool :)  Besides, if it is damage the cover/case a bit or throw it away, pry away :)

Thanks everyone for all your help. I will give your screwdriver suggestion a try, hehe. Sorry, didn't mean to insult Dell computers, but I do think it would be a much better design to have a screw on/off cover rather than the button/sliding mechanism. I don't think it has been dropped or anything, but it has been moved cross-country so, who knows. It's probably glued shut with tar. Is there anything worse than smoking around electronics?!

There is nothing worse that smoking ... period.

Thanks everyone for all your help. I will give your screwdriver suggestion a try, hehe. Sorry, didn't mean to insult Dell computers, but I do think it would be a much better design to have a screw on/off cover rather than the button/sliding mechanism. I don't think it has been dropped or anything, but it has been moved cross-country so, who knows. It's probably glued shut with tar. Is there anything worse than smoking around electronics?!

if you think its glued with fag residue id apply some spray solvent to the edges which are supposed to slide with machine SWITCHED OFF! its nasty stuff that fag residue we often had to apply solvent to open customers tv and vcr casings who must have been heavey smokers,youll nevr fully get rid the smell when its on but i guess vaccum ing the dust will greatly help

Maybe you could hang an air freshener inside :)

There is a Single Screw holding the cover on sometimes.  You need to remove the screw then push the latch and slide the side cover off.

Its best to lay it down then press the latch to slide the side off.  It wont pull off it has to slide off.  Back slightly then up.

Removing the Computer Cover

Dell™ Dimension™ 1100/B110 Systems Service Manual

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions located in the Product Information Guide.

CAUTION: To guard against electrical shock, always unplug your computer from the electrical outlet before opening the cover.

1. Follow the procedures in Before You Begin.
   
   
2. Lay your computer on its side with the computer cover facing up.
   
   
3. If your computer cover has a cover latch, slide and hold the cover latch.
   
   
4. Grip the indents on the computer cover, and slide the computer cover toward the back of the computer.