Slic3r file too big to slice for printing

S3D has no issue with files that large. But file size depends on your method of creation.. Is your CAD software additive or subtractive?

I use Tinker CAD and it uses basic shapes and those can be solid or holes. However with the way it works even the holes take up file space so the more holes you create or the more negative shapes you use to shape your desired shape then the bigger the file gets.

Refining the triangle mesh will increase the number of faces/triangles, not lower it.  But then again, I don't have access to the Refine function, since I only have Netfabb basic.

So, you have a Pro version of NetFabb?  Lucky you....

no not computer memory nor processor, slic3r takes forever does nothing then crashes with errors about not able to find/write data. and I just have basic Netfab also. remove degenerate faces' is what I used. it also has values you can set

apps like a Slicer and related programs to it have buffer limits and cache limits in them and when they are reached just loading the file then no room left to modify it.

kind like on a paper printer when you click to print say a color Photo the printer board and computer Ram both need enough space to "spool" print data b4 printing begins. like streaming data also. some systems have advanced settings to adjust these limits if virtual memory is used on an HDD.

I'm not sure why you had to make 4 separate posts, but let me see if I can answer some of these. 

no not computer memory nor processor...
I'm still not sure what it is you are running, whether it's XP, or Win7, 32bit, 64bit,  You never really made it clear, but I can tell you that Slic3r uses memory and processor to do it's thing.  I suspect that the same problems you had printing the simple parts for the Atlas 3D printer are surfacing here as well.

remove degenerate faces' is what I used. it also has values you can set
That has nothing to do with polygon reduction.  Worse yet, it's a function that usually distorts the surface and creates more problems that it solves.  It will remove a face which it thinks sits on a degenerate edge, removes it, which creates additional degenerate edges, removes those, and so on, then fills the surfaces without any though to the original; shape. 

I never use that function, I'd rather leave them in place as they don't affect the model in any adverse ways.  Perhaps this is why you're having such problems with your models.  You let NetFabb "fix" them and instead it messes them up.

another thing that loads space in files is lots of changes made over several times. it saves things like old parts posistions etc.
Well, the first part is true, making changes over time, it will affect the final size of the file, it could be larger, or smaller.   
STL is a pretty simple format, it stores triangle information, their relative scale, and location from origin, that's it.  The scale and location information doesn't take up any space to speak of, the data is very small (a few KB).  It's the number of triangles that take up space.  So the more "refined" a mesh is, the more triangles it has, so the larger the file is.  If your file blimps out of proportion, it's because it got more triangles.

apps like a Slicer and related programs to it have buffer limits and cache limits in them and when they are reached just loading the file then no room left to modify it.
Sorry, but it doesn't look like it.  The fact that I can load and slice a 200MB file is proof of it.  There might be a limit, probably imposed by the amount of available RAM and scratch space on your HDD, but you shouldn't see it with a small file like the one you originally mentioned.

Bottom line, you're having the same problems here, that you had printing the Atlas 3D parts.  There you refused to acknowledge that the problem is at your end, and blamed the STL files, even when everybody was telling you there was nothing wrong with them.  Here you look at Slic3r as the culprit, when really it's something else on your end.

I don't think you'll ever be rid of any of your issues until you face the fact that there's something else wrong with your system as a whole, and start overhauling it from scratch.

Let's put the hardware aside for a moment and deal with the STL.

STL files can be found (or saved by a program) in either ASCII or Binary formats.  The ASCII format is a text format that is readable in any text editor.  Each triangle orientation location is described individually, which is why ASCII STL's can be very large.

For this reason, the Binary STL format was developed, and because of the way it describes the object, it's a lot more compact than an ASCII STL. 

So as  you can see, the ASCII version is more like the uncompressed bitmap you were talking about, whereas the binary is more like Compressed TIFF or PNG.  It's not, nor will it ever be like JPEG, because JPEG is a lossy compression, whereas a lossy compression for STL files would involve modification of the geometry.

Now let's talk a bit about your computers and the setup.

You ThinkPad T61 is pretty outdated.  The Core 2 Duo T5500 benchmarks on a par with an Intel Atom Z3735G, which ain't exactly fast.  Then you are hampered by having only 3GB of total memory.  You said you're using 16GB of virtual memory.  That might actually be a problem.  First of all, on 32bit OS, the maximum usable virtual memory is 3 times the size of the RAM.  Take a look at your pagefile.sys.  What size it it?

Then there's the issue of performance.  Your virtual memory is only as fast as your hard drive.  The average laptop HDD is only 5400 RPM, and that's pretty slow.  Then, because this is a laptop, there's only one drive, so the same drive that holds your OS, also holds your virtual memory.  All these things will affect your performance negatively.

I also have a large HDD partition for swap file on my computers.

If you're putting your swap file on a separate partition of the same physical drive, make sure it's the only one (in other words you don't have a Swap file on that partition and one on the main drive.  That will impact the performance of your laptop negatively.

I would let Windows handle the virtual memory, and not attempt to manually control it.  Windows is pretty good at it, and it will increase, or decrease the file size as necessary to handle the applications that are needing the extra memory.
As far as slicing models, I suggest you get one of the later versions of Repetier Host that has Cura, and give it a try.  You'll find that it a lot easier to use, more forgiving of errors, and a hell of a lot faster.

Last but not least, regarding your T61.  If you're happy with it, that's fine.  When I said it was outdated , I mean it in terms of hardware generations.  There have been 7 CPU generations since that processor was introduces back in 2007.  We are now into the 6th generation of Core i processors, and the next gen microarchitecture that was introduced with the Nahelem (the first Core i5/i7) changed everything, and dramatically improved performance.

The bad news, is that the maximum amount of RAM T61 can have is only 4GB.  The chipset doesn't support any more than that.  The good news, is the THinkpad W500, assuming you have a Core 2 Duo T9xxx CPU, has a GM45 or PM45 chipset which does support more, it can support up to 8GB  of DDR2. 

Considering the cost of a 4GB DDR3 SO-DIMM is about $25, for $50 you can upgrade your notebook to 8GB.

If you want desktop features, why don't you simply get a desktop PC? 

Rather than spend the money on a 4 year old refurbished laptop that weighs nearly 6lbs., for the money you'll probably get better hardware and features, and ultimately real upgradeability in a desktop.

its plenty for 3D printing needs. more memory and higher speed PCU wont do any better, faster printing.

and as to Pirvans getting a desk top; been there done that, I find it much more difficult to pack-up and carry all the components of a desk top in 1 bag when traveling LMAO plus it takes up way more work surface area. my last old hand me down custom built  desk top had a RAID 4 HDD plus tons of other cards installed for surround sound, graphics TV/radio multi drive bays in a tall tower with 5 big cooling fans filtered like for a server and a huge HD monitor (pre flat screen), large keyboard and mouse that cluttered my desk beyond usability and weighed like 60 plus pounds and would need a large steamer trunk to haul it in plus another for any peripherals which I have many (one portable printer/scanner for my laptop bag)  its been retired to the basement train room (monitor replaced with flat screen). see my 2 sons are BS IT guys been building their own since grade school with careers at big corps. so Dad gets plenty last year models lol.

well many other apps running at same time can mess up RH/slicer functions. especially high useage things like games, flash, streaming, media as they use that memory and some background support apps also. plus look what Atlas 3D scanner does just on an Pi its very limited memory

Thanks! that was my backup plan lol