Running

Is QuickField also running with Netscape 7.0 (setup program requires Internet Explorer 4.01 SP2)?
QuickField needs Internet Explorer (IE) to view html-help (QField.chm). This help is opened by the hh.exe program (included in Windows) that uses IE-engine. The browser does not start. Only its components (dll-files and other files) are used. The IE is a part of Windows. You cannot have Windows without IE. So that is not a question of existing IE, but a question about version of IE and Windows. In Windows 95, 98, NT the IE can be older then needed. Netscape cannot help here.

I downloaded the Student version of QuickField recently But I haven't succeeded on solving the most simple problems Because I get this error message of 200 nodes limit. What's the problem with this program, is it a kind of setting. Or what?
QuickField Student is restricted by 255 degrees of freedom. You may try to fit to this range by manual setting of mesh spacing. Professional version has no artificial restrictions for mesh node number. Professional version is fully compatible with the Students version in file formats, and has the same postprocessor.
QuickField.com > Product > Editions

I have QuickField Professional single license. When started locally it works fine. When started over Remote Admin I got the error message "FindNextUnit failed with status 71 (INVALID LICENSE)".
Running single license through remote access is prohibited for security reasons. You need network license for that. See more: http://sentineldiscussion.safenet-inc.com/topic/using-key-through-remote-desktop-or-terminal-server

How can I refine / unrefine the mesh size in certain areas? I need a refined mesh size in a certain area of my model. But by now I have found a possibility to refine ALL meshes only, as the "old" meshes disappear as soon as I choose a new size. When rebuilding the meshes, all are created according to the new value, which leads to excessive calculation time. For refining, I use the "Selection Properties" > "Spacing" > "Manual" function after pressing ALT-Enter.
Sorry, not possible. It works as you described, either automatic refinement for entire model or manual refinement for any part.

On your web page you show a new feature for adaptive meshing (solve and refine). I was trying to find this new option and I couldn't ! Each time I try to solve already solved problem software immediately wants to show me results.
This feature disabled in Student edition. You cannot refine with only 255 nodes available.

I'm working on binary images obtained by processing 16-bits images of some alloys and I'm trying to use directly these binary images to describe the geometry of the problem.
QuickField understands DXF files only. So you need to convert Bitmap > Vector > DXF.

Is it possible to define an arc of a given radius between two end points?
QuickField has very simple geometry editor. There is no way to plot an arc with specified radius. You need to calculate an angle manually. Or you can draw the model in some other CAD and then pass it to QuickField through DXF export/import.

When I want to look at the results QuickField come up with a message saying that the solution is out of date. Is there any special way I have to save the results to be able to see them again later?
The problem related to the wrong data settings on your or other computer where the files were modified. Say you got files all dated year 2020. Then you solve the problem on your computer and got the result dated current year (2014). QuickField sees that the result file is old (comparing to the problem file).
Use Save All command to update all files dates. Then solve the problem again.