This value sets the maximum number of files that can be opened by the runtime system. The default value is "32". Keeping this value small conserves memory. Many operating systems limit the number of files that can be opened by a single process, so you may have to make some adjustments there too. The highest allowable value of MAX_FILES varies with the operating system:
| System | Max value |
| UNIX, MPE/iX, VMS | 255 |
| MS-DOS, OS/2, Windows 95/98 | 128 |
| Windows NT 4.0/5.0, Windows 2000 (32-bit) | 256 |
| Windows NT 3.5 or 3.5.1 | 64 |