Microsoft Outlook is setup to block potentially dangerous filetypes
e.g. .exe, .bat, .pst etc.
If you fully trust the attachment and need to download it them update the registry using Start –> Run –> Regedit
and change the settings as suggested by Microsoft here ==> CLICK HERE
PLEASE NOTE, this has the potential to ruin your Operating System so do not use this if you are unsure and/or have not backed up your registry first.
PLEASE AlSO NOTE THE DISCLAIMER AT THE BOTTOM OF THIS PAGE