C Drive Read / Write

What error message is given?

Access is denied for the company owner (domain admin account) all ok for the other domain admin account

Normal behavior since windows xp. Only admins may write to c: directly. ON your system where it does work, the UAC is off while on the other, it is on.
3 solutions:
-don't write to c: but use a folder
-turn off UAC
-change access rights on c:

Thanks McKnife but its a folder off C:

I understand that people can't normally write to the C:

We don't want to change the access writes as it works on another computer thats next to it with the same settings

Ok, please show the access rights using a screenshot.

Right click the folder and take ownership of the folder.

https://support.microsoft.com/en-us/kb/308421

Domain admins (as a group, so all of them) are by default in the local administrator group, so the selected solution could not have any effect. What solved it?

Looks like the company owner is using a domain admin account which is not a default Domain Admin. That's why it is not in local admins group. I have seen this problem with XP very often when trying to deploy the software to remote XP machine which is part of AD but even using the DC Admin account it failed. Till I added on XP locally the account to admin group.

You are not admin until you elevate - same for domain admins. But: if you put "his" domain admin into that group "administrators", it cannot be different since elevation needs to take place anyway.
The only user that does not need to elevate is the account "administrator" (no matter if domain or local account).

So he will have done other adjustments as well, like tuning the ACL to feature his admin's name, directly, I guess. Right, James?