Major/noticeable changes to version 2021.05.01.
vDos.exe is once more smaller (for if you would question that). Some 15% CPU overall speed gain, though FoxProX code will run up to 50% faster. Priority of vDos.exe set to “High” to give it a slight advantage when competing with other programs for CPU attention.
Detection of extensive keyboard polling by a DOS program: vDos will then drop to idle mode sooner.
Print processor passes on eventually set copies option and the like to the print driver.
Text is transferred as strings instead of individual characters, resulting in smaller Windows print jobs and PDF's.
Added a bold variant of the internal font (can also be used for display).
Changed the DOS DTA based find file API to Windows search handles conversion strategy.
Support of extended ASCII characters like é and ö in directory and file names. Note: If such a name cannot be converted to the current code page in vDos, those are hidden/inaccessible.
Switched from Windows GetBinaryType() API to examining the header bytes to determine a file type.
Screen DPI awareness: vDos renders text at the (sharper) native resolution if Windows is set to scale content.
Added a simulated dark mode of the DOS screen (probably a gimmick?).
Changed WINDOW= to size%[,horz%:vert%] for more consistency and uniform positioning. “Set as default” system menu option added when the window is resized, saving the window size and position to config.txt.
Some refinements to command line parsing. Redirecting output was 'sticky', it stayed active.
Redirection of Windows CMD or START command are no longer trapped by vDos command line processor.
Forced pasting text in programs that bypass INT 16.
Extended functionality for select/copy text. See the last paragraph of Printing.pdf for details.
Faulty EXEPACKed DOS programs will load/start correctly w/o external help or sacrificing the first 64KB DOS memory block.
Download: Installation program 2021.05.01 | Source files and older versions
First read the little documentation vDos has to offer to make it run your application! Keep in mind you once had to configure DOS, the transition to Windows (XP?) took time. You forgot about that…

Have a look at the FAQs and Forum pages, eventually post your question/problem to the latter. The forum is monitored by Edward Mendelson and me, replies are mostly real quick.
If your issue however seems real specific to your situation/application, or you don’t want it public: Send an email to (change the "a" to an "o").

Submitting a problem or issue: Describe it as detailed as possible, eventually attach your autoexec and config.txt files. If your autoexec.txt starts another batch file, include that also. A mere “My DOS program won’t …” doesn’t help to come to a solution, how simple that even might be...
Trouble downloading: Check if you’re using a download accelerator and disable that.