Is C:\WINDOWS\system32\DDMI.sys malware?

Hi I wrote a post last night but looks like it didn't take.

My computer will not allow me to open a Microsoft Works document I was in the middle of working on. It says it has to use a converter to open it. Then says my computer doesn't have the converter.

Also it will not allow me to attach it to an email I was going to send to myself to try and save it when I redid it.

Also it will not allow me to save it to a flashdrive because it says only the administrator can do that. It has always let me do this.

I don't know if it is malware or if it is connected to blocking or allowing the wrong things on my online armour firewall, or if has to do with recently downloading Hewlett Packard printer and repeatedly clicking allow for my firewall to allow the download of lots of stuff.

THere are many things I'm not sure what they mean, one thing on my firewall accept list is C:\WINDOWS\system32\DDMI.sys

Thanks,

Cinder Edna