>Thanks a lot, but are there any method to avoid this under Windows 95? I can't change the DOS application (is the entire gestion of a hotel) and is made in Clipper.
>A lot of thanks another time!

Probably not under Win95 or Win98 because of the underpinnings of the memory management subsystem, but you might be safe under Windows NT.

You may be able to play with the MS-DOS settings for memory management of the DOS session under Win95 that runs Clipper, but my own experiences with Clipper apps doesn't hold out much hope. Under the MS-DOS program, examine the Memory tab. Make certain that the check box for 'Protected' conventional memory is checked; this ensures better isolation of the DOS VM at relatively little cost in terms of usable conventional RAM and performance. Also, under the Misc tab, check Always Suspend under Background to keep Clipper from doing strange things when not in the foireground (this won't help if the DOS app has to monitor ports, etc.)

NT provides much better isolation of Win32 apps from the DOS VM; you may have trouble getting the DOS app to run if it accesses hardware at a low-level due to NT's HAL.