Thanks for posting the information above. After reviewing a number of memory dump files, our engineering team has determined the following:
- Windows XP leaves approximately 12,000 bytes of shared stack space for kernel modules to share.
- Windows provides no way to identify available stack space; it just BSODs when the stack overruns.
- PGP WDE 10.0.2 and below use approximately 600 bytes of stack space.
- In the PGP WDE 10.1, we proactively reduced this to approximately 100 bytes of stack space.
- KB 2393802 leaves less stack space available in the Windows kernel for other kernel modules to use.
- PGP WDE (pgpwded.sys) is generally the last driver loaded. As a result, when we try to grab our modest stack space, the blue screen will display our driver name as the responsible driver.
- In our testing, almost every system suffering from this problem used the Intel graphics driver. This uses about 7,000 bytes(!) of stack space. Without this single driver using over half of this available shared resource, there would be plenty of room for the WDE driver.
The above explains a number of items:
- Why the problem occurs on some systems but not others
- Why it occurs without PGP WDE installed
- Why it occurs most often on Win XP
- Why we did not see this in our testing
Our current recommendation is to upgrade to PGP WDE 10.1.1; the lower stack utilization allows it to fit in the reduced area. Thus far, we have not seen a case where this did not fix the problem; the reduction in available stack space from the MS patch must be less than 500 bytes.
As said in a message above, there is no need to decrypt your disk before upgrading to 10.1, though we do recommend a backup as a basic best practice.
Also, we have not been able to duplicate this on Windows 7. If you have seen this issue on Win7, please post here and let us know if we can reach out to you to see what's happening.
Unfortunately, this is a difficult situation for a software vendor like us. We're doing the right thing in minimizing our use of the stack - in fact, we proactively reduced it further before this issue even occurred. However, a combination of other programs' behavior and our position in the driver loading process (probably because we were installed last) makes Windows crash with the finger pointing at us.
Please leave a note here if you use the Intel graphics driver and have seen this issue. I'll be reaching out to Intel to see if they can update their video driver to minimize stack usage.
My apologies to anyone affected by this issue.
Bryan Gillson