Honestly, if you have never modded a BHAV before, the computer is not the place to start.  It's an extremely complex set of BHAVs just to do simple things, and , in my opinion, your desire is a little more complex.

If you are set on trying, start with the tutorials on MTS and then build your skills beginning with very simple mods, browse the objects.package and mods of others.  You will eventually reach a point where you can make heads and tails of the computer behaviors and then start to change them.  If you're lucky, after around 6 months of studying and trial and error.

@ Raven  Just to clarify, chairs, tables and desks have no behaviors associated with computers.  They are simply surfaces to put things on.  Everything related to the computer are tied to the computer.  This include what the computer can be placed on, what the sim would sit on, and what animations are used.  

@ajy There is a semi-global that checks to see what kind of chair is being used (dining chair).  It may be possible to modify that BHAV to have it additionally check for the barstool.  The nightmare is the semi-globals for the computer are truly like a plate of spaghetti.  There may be additional places the chair is addressed.  There may be places the surface, table or desk, are addressed.  

Most have confused the computer with a modded computer... Anyway, it doesn't really matter.

The "stools" are the barstools. They don't come with computer access, and they come with different animations. Hence why you might need that invisible chair I was talking about. The shiftable invisible chair can be placed so that the sim sits down on this, but it looks as if they're sitting on the barstool. Same if you had an invisible, shiftable desk, which can be placed anywhere and in most heights (counter included). That way you could use any computer, not just the cheap computer but CC computers, too. Computers are pretty much the only objects that needs three objects cooperating together to work. Most other objects just needs a proper surface, and it doesn't really matter (except for the animations) which height that surface is in. You need a chair and a desk for the computer, which means they interact somehow.

I'm pretty sure someone would have figured this out already if it wasn't for the complexity. It's one thing to make a microwave accessible from a floor position. Animations look weird, but since the sim doesn't need to sit or do anything special, it's possible as long as the item thinks it's on the right surface and it is accessible for the sim somehow.

Useable items that can be placed anywhere are only useable if the sims can gain access somehow. In case you haven't noticed, only one side of the desk works for computer access. The other side is essentially just a table, and without a cheat you can't place the computer there. It's the same for making food on any other surface than a counter or isand. It's not possible without either a heavily modded object or a "simple" shiftable OMSP with counter function.

In either case, I doubt this is a good starter project if you haven't done any modding earlier.

I'm not familiar with that particular computer, but if it has regular computer animations you'll need a table or desk to make the coputer have animations that can let a sim use it while sitting on a chair.

I don't think your problem is making the computer placeable on all surfaces. I think the problem is to make it useable on those surfaces. The best way would probably be an invisible, shiftable desk of some kind, so a chair can work together with it, and so sims can use the items on the desk without any routing troubles. It could be placed over a counter, and that way the computer would (most likely) be useable. It might look a bit strange with the counter (depending on which type of counter it is), but that would probably be the case no matter how you choose to do this.  

It's easier to mod objects sims use when they stand up. The moment you need 3 items for an item to work and be usable (particularly computers) things get a bit complicated.

- If I modify the height of computer, using SimPE, I can place computer any surfaces.
- If I modify the height animation of computer, using some program including SimPE, I can make animation of computer work with when I place the computer to any surfaces.

Try not to double-post, please.

I think you need a table with the functions of a desk to make computers work properly, simply because the desk and the chair sem to work together to gain access to the computer.

If you have AL it could be possible to make a shiftable desk, and you could use the shiftable chair OMSP from here to place in front of it. They would at least sit in somewhat the correct height. Can't guarantee it would work with the computer, and the animations would probably look a bit off, but that's probably the easiest way.

I don't think there's a lot you can do about the height of the animations. I also don't think it's possible to make a "standing up" computer without some serious animation and modding work - if that's what you want to achieve.

As for placing on all surfaces, you might get lucky with Numenor's batch fix tutorial.
I can't guarantee it will work on a computer, though. It works (sort of - not for IKEA or M&G shelves) for deco items.

If all goes wrong, there's these OMSPs. Animations might be off, and computers that require sitting down to use them might not work. You would be able to place the computer anywhere, though.

I don't know a thing about animations, but I would think there's something tied to the animations, surface, or computer that indicate the height of the animation.  If there is and you find it, you could play with the numbers to see what would work for you.

- Made so that I can place the "cheap computer (moneywell)" on any surfaces (i.e. table, desk, counter).
- Figured out that I need to edit "cheap computer (moneywell)" using SimPE.
- Figured out that I need to edit the height of "cheap computer (moneywell)"'s animation.
- Tried to edit various part of packaged cloned "cheap computer (moneywell)" in SimPE.

- Make "cheap computer (moneywell)" able to place on counter.
- Make the "cheap computer (moneywell)" animation work properly, just like when I placed it upon the desks/tables, using the stool, not only just dining tables.

How do I suppose to do what I want to do just like what I wrote on above?
Are their anyone who can do modding for animations of objects can help me with my problem?

I made one. You can find it here:

http://www.the-isz.com/theisz/index.php?showtopic=4668

This isn't a new machine. It is a mod that effects all Hot Beverages in the game.