Weird error trying to read the registry - CVI 2020

[HowardE]

I'm sure this is obvious to someone but...

I need to read and then write a registry value from my CVI program.  I found examples of RegReadString  and came up with this test case:

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unsigned char buffer[260];

unsigned int size = 0;

static const char *subKey = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders";

static const char *valName = "Common Documents";

status = RegReadString(REGKEY_HKLM, subKey, valName, buffer, 259, &size);

MessagePopup("foo", buffer);

static const char *subKey2 = "SOFTWARE\\BAE Systems\\MyApp";

static const char *valName2 = "Data_directory";

status = RegReadString(REGKEY_HKLM, subKey2, valName2, buffer, 259, &size);

MessagePopup("foo2", buffer);

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The first  read works fine and pops up the expected result.  The second one is supposed to be the same thing, except I creates a new subkey other tham 'Microsoft'.  I created my subkey and string value in regedit and I can see it.  I also made sure that the registry permissions are full access.  What happens is that the read fails with an error -5070 and buffer is simply not written.  What am I missing?

Your next cup of coffee is on me if you know what the problem is.  Thanks!  This is a major showstopper and I'm just not finding answers on the web.

Howard

[rolfk · Accepted solution]

-5070 is error ToolErr_MissingKey. It means that your "SOFTWARE\\BAE Systems\\MyApp" doesn't exist in the registry.

Most likely reason: You are running a CVI 32-bit application on a Windows 64-bit system. Windows will redirect all registry requests from a 32-bit app to "HKLM\\SOFTWARE\\xxxxx" to "HKLM\\SOFTWARE\\WOW6432Node\\xxxxxx" instead.

Your "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders" exists in both places (not necessarily with the same contents though), so you thought it was reading "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders" but it was really reading "SOFTWARE\\WOW6432Node\\Microsoft\\Windows\\CurrentVersion\\Explorer\\User Shell Folders"

[HowardE]

Awesome - thanks!  It is a 32-bit app on a 64-bit machine.  I had finished implementing a solution with .INI files but I may go back and tweak it.

The offer for the coffee is good. I can share my email here and we can discuss a way I can send a credit of some sort.

This is why I love these forums - someone here always knows the answer to every question.

Howard

[rolfk]

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@HowardE wrote:

Awesome - thanks!  It is a 32-bit app on a 64-bit machine.  I had finished implementing a solution with .INI files but I may go back and tweak it.

The offer for the coffee is good. I can share my email here and we can discuss a way I can send a credit of some sort.

This is why I love these forums - someone here always knows the answer to every question.

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You are welcome. 😁

If you are really inclined to part with a little bit of money of some sorts, please consider doing a donation to some good cause of your choice. 🤗

[HowardE]

A donation to the NH state science fair will be in your name.  Thanks!