VB.net 2010,Windows Desktop Excel ADODB Provider cannot be found

[QuickBooksDev2]

Hi,

We have a VB.2010 32 bit Windows Desktop program that has been running for years. It uses an Excel (2010 in this case) database which is accessed through a connectionless OLEDB connection string as
Provider=Microsoft.ACE.OLEDB.12.0;DATA SOURCE='L:\accnt\CustomerFiles\DATABASE 2015.xlsm'; Extended Properties="Excel 12.0 Xml;HDR=YES"

Normally it works fine but on some systems we get a
3706 Provider cannot be found.

It has failed and worked on different W2012R2 systems. It also has failed on Windows 8.1 (64b).

On W8.1 have tried installing AccessDataEngine_x64 but it did not help (32 bit version would not install).

Can anyone help?

 

[ChrisM]

Do you still have users on Excel 2003 or earlier? Don't think they'll have the ACE 12 provider.

Is everyone mapped correctly to your L: drive? Maybe some users have an additional subfolder mapped in to their L: