Hi Ed,

Thank a lot for your advise and comments. I appreciated it a lot.
For your information, I only using a grid, command button and timer
control only. Is any of the control above know to cause problem.
Next, most of my application error happen when the timer trigger
the code inside the timer event only.
My VFP5a is patch with service pack 3, running on WinNT 4 with
service pack 05 only.





>check>Hi,
>>
>>Thank for your advise. I know VFP had error of 0xC0000005.
>>My company had not yet decide to upgrade our vfp5 to 6.
>>It strange why some VFP written application had this error whereas some
>>don't had, must be some way or things that we do causing this problem.
>>If you know of which area are likely to cause this problem, please advise so
>>that I can tried to avoid it. THank a lot
>>
>
>The C...5 error is a generic memory exception - NT caught something trying to read or alter memory that it didn't have the necessary permissions to access, or referencing a memory location that didn't exist. This may be a problem residing in NT, in VFP itself, or in a third party product.
>
>I'd check to make sure that the NT system has the current Service Packs for NT applied (the most recent is NT SP6, about a 34MB download from the MS web site, available from MS for a relatively small amount of money on CD.) For me at least, anything pre-SP5 is very suspect, and MS will probably tell you to apply current patches before trying to find a problem if you contact their technical support.
>
>I'd also switch to the vanilla VGA display driver to eliminate video drivers as a suspect.
>
>You also try to curb VFP's appetite for NT's memory - try explicitly setting foreground and background values for VFP's buffers using SYS(3050) - by default on a relatively (for me) small memory NT system with 128MB of RAM and about 300MB of swap space, VFP defaults to letting itself grab 80MB of RAM if left unchecked; I tend to set values significantly lower, especially where VFP would tend to hit the swap file - virtual memory = disk access. YMMV.
>
>You should also try to pin down the block of code that causes the problem - if it consistently happens in the same place, you may want to look at recoding that section of the application or using different controls if it's happening in a Form. Once you've pinned down a cause, there's some hope of finding a resolution or workaround via the MS Knowledge Base - without a specific cause, there are a ton of things that might avoid the problem, but guessing on the basis of just the C...5 error is taking shots in the dark, SWAGs at best, and possibly worse than what's happening now.