Unable to load .dll, plus DirectX error

[caro7]

After being informed by Motu tech support to download DirectX, I get the following message: "An internal system error occurred.
Please refer to DXError.log and DirectX.log in your Windows folder to determine problem." However, there is no sign of either of these in the Windows folder. I am using Windows XP offline, so it was the DirectX End-User Runtime Web Installer (directx_aug2009_redist.exe) I was trying to install. As the PC has not been connected to the internet for a couple of years, web browsers and anti-virus/spyware software are uninstalled.

The error message I was previously getting which prompted Motu to advise me to download DirectX was 'Missing application element - Unable to load 'C:\Program Files\MOTU\Ethno Instrument\Plug-in|Ethno.dll'. Please reinstall the application or contact technical support'. However, when I look in that folder I can see that .dll file is there. I tried reinstalling the older version of the software (Ethno. 1.0) and restarting and that didn't work; I then did the same with the update again but still get this message. It doesn't seem to be a problem unique to Ethno however as the Symphonic module also refuses to load.

Other information which might be useful for any kind person willing to help this damsel in distress:

- There appear to be 3 administrator accounts - the original one (which I think was disabled by the tech guy I bought the PC off - I can't use it in any case), and two more in my name. Would deleting any of these help? Or am I in trouble because any changes I would need to make would be under the original administrator?

System information is as follows:
OS: Windows XP
OS version: Professional
CPU: 1.10GHz
RAM: 1.25 GB

Also, I have updated the graphics drivers (after uninstalling them, as per Motu's advice).

Finally, I am not techy at all so if anyone giving advice could keep it as simple as possible I'd be really grateful. Thankyou very much in advance for any help, I have reached desperation point!