Receiving this error from code which is attempting to access a MS Access mdb file
Microsoft OLE DB Provider for ODBC Drivers error '80004005'
and/or
[Microsoft][ODBC Microsoft Access Driver]General error Unable to open registry key 'Temporary (volatile) Jet DSN for process 0x4b2cc Thread 0x782b0 DBC 0x1d25bb4 Jet'.

Also experienced on IIS7 as:

[Microsoft][ODBC Microsoft Access Driver]General error Unable to open registry key Temporary (volatile) Ace DSN for process 0x13b5c Thread 0x43ac0 DBC 0x25d1004 Jet'.

• On IIS 6: Usually means your website user doesn't have necessary access READ AND WRITE to the directory where the MSAccess mdb file is stored.  You can open a support request referencing this article, your error, and the location and filename of your MS Access mdb file.
• On IIS 7: This is due to a change IIS 7's behavior for loading of user profiles for application pool identity, thus changing the TEMP directory used by PHP or ASP when interacting with the MDB file.  Please contact support for assistance and reference this KB article, along with the URL on your site that is generating this error.