Okay so first of all, our design drawings are supplied in Adobe pdf file format. This means that you will need an up-to-date version of Adobe Reader to open and view your attachments.
Please visit https://get.adobe.com/
Alternatively you can give us a call on 0330 223 0149 and we'll guide you through some troubleshooting steps. Remember that we're here to help... and save you from destroying your computer:)
Our kind regards,
The 3rd Storey Team.