Authentication (Windows & Forms)
Preventing Common Authorization Problems
Attempts to launch UploadZen from a Document Library may yield a HTTP 401
error message, or UploadZen may repeatedly prompt for a user name and password
that won't work even when specified correctly for a Full Access account, unless
and until you take all administrative actions required to
prepare a Web Application for UploadZen.
Automatic Authentication (Single Sign-On) Attempts vs. Log-In Prompts
Under certain circumstances, UploadZen users may be prompted to log in to SharePoint:

Generally, UploadZen will attempt to log users in to SharePoint automatically,
if and only if:
- the SharePoint Web Application from which UploadZen is launched uses the
Windows Integrated authentication mode, and
- the user who launched UploadZen was logged in to SharePoint as the same Windows
user account used to run their Internet Explorer process.
Consequently, users may be prompted by UploadZen to log in to SharePoint:
- if the SharePoint Web Application from which UploadZen is launched uses the
Forms-based Authentication (FBA) mode, or
- if the user who launched UploadZen was logged in to SharePoint with a different
user name than the one they used to run their Internet Explorer process, or
- if they never ticked the Internet Explorer check box 'Remember my password' when
signing in to SharePoint, or
- if their Internet Explorer or Windows security settings prevented Windows from caching
their user credentials for this SharePoint Web Application for later use by other
trusted applications, or
- if UploadZen was denied access to previously cached Windows default
credentials for the SharePoint Web Application for any other reasons.
Saving User Passwords Locally
When users are prompted by UploadZen to log in to SharePoint, they can elect
for UploadZen to store their encrypted password in the Windows Registry
Local User hive and use it automatically in future upload sessions. To disable this
option for your some or all of your users, consult the appropriate
server-side configuration setting.