Cannot scan without admin rights - Epson Perfection 1640SU

[Tightpants]

We have an Epson Perfection 1640SU connected to a workstation on the network. The scanner will not scan unless the user is given administrator rights. Even power user rights will not work.

Each time you try to acquire something an error message appears on the screen saying that Twain is not installed.

The scanner is connected to the workstation via USB.

I have contacted Epson support and they told me to change the permissions on the C:\WINDOWS\TWAIN_32 folder however this has not helped.

Any ideas?

 

[Rick998]

Did the scanner installation offer the option to install for 'all users or just current user'?

If there wasn't such an option (and there often isn't for older drivers/software) then you may need to change permissions within 'C:\Program Files\'.

You may also need to make changes within 'C:\Documents and Settings\<USER>\Local Settings\Application Data' (where <USER> is the account name of the logged in user).

Have you also tried changing the permissions in the registry? (For example, adding the 'Power Users' account [or the 'Everyone' account'] to HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Twain).

You would need to either run regedit.exe whilst logged on as an administrator and amend the settings for the appropriate SID in the HKEY_USERS area or (much easier) log on as the appropriate 'Power User' then run regedit.exe using 'Run As...' [Administrator] and amend the permissions under HKEY_CURRENT_USER.

The reason for this is because only the Administrator account or an account with Administrative privileges can amend the registry permissions within HKEY_LOCAL_MACHINE.

Lesser-privileged accounts can only amend within HKEY_CURRENT_USER. However, if (for example) the Administrator is logged in then HKEY_CURRENT_USER is actually just a copy of the Administrator's SID stored in HKEY_USERS, i.e. HKEY_USERS\S-1-5-21-xxxxxx-xxxxxx-xxxxxx-500. The Administrator SID always ends in -500 and the first account created after installation of XP usually ends in -1003.

To determine the SID of the account you want to change permissions for, have a look at

http://www.microsoft.com/technet/scriptcenter/resources/qanda/dec04/hey1203.mspx.

Once you have figured out which registry keys need their permissions changed then you could carry out the same changes in the SID for .DEFAULT.

An alternative method which may work is to temporarily add the lesser-privileged account to the 'Administrators' group, un-install any scanner-related software, remove the scanner from Device Manager then re-boot.

Log back in as (temporarily-elevated) user and install scanner drivers and any scanner-related software. Once you've checked all is working, remove the user account from the Administrators group and re-boot.

Finally, a method I use for particularly problematic software is to monitor the driver/software installation using tools like InCtrl5 (

http://www.devhood.com/tools/tool_details.aspx?tool_id=432).

This builds a list of all changes made to a PC so I can see exactly where I need to be experimenting with permission changes.

Hope this helps...

 

[bcastner]

You need to add NT Rights to load and unload device drivers.

Start, Run, gpedit.msc

Local Computer Policy
Computer Configuration
Windows Settings
Security Settings
Local Policies
User Rights Assignment

Give 'Everyone' GROUP the right to Load and Unload device drivers.



____________________________
Users Helping Users

 

[Tightpants]

Thank you for the suggestions but unfortunately none of them solved the problem. I am going to try a SCSI connection instead of USB to see if that makes any difference. If that doesn't cure it I will try the InCtrl5 tools in the earlier link.

Thanks for your replies. I will let you know if I solve it.