Unable to install windows

[TjuBom]

I just wiped my harddisk completely, and when I tried to boot up the computer it is telling me that it is missing files, so I found the original disk I used to install windows with on this exact computer, and it is telling me that the disk is incompatible with the version of windows I have?
Also I can't select a disk to install windows on because they're of the diaktype GPT, but I had no problems installing it 2 years ago when I assembled the computer?

 

[RARRAF]

so tell us what version of windows are you trying to install????

 

[TjuBom]

I'm trying to install windows 7, with the original disk I used when I first assembled the computer

 

[USAFRet]

You need to boot from the install DVD
Wipe all the existing partitions
Continue with the install

 

[TjuBom]

I've tried, but when I come to the point where I need to select a disk to install windows on, it says that the disk is the wrong type (GTP)

 

[USAFRet]

I've tried, but when I come to the point where I need to select a disk to install windows on, it says that the disk is the wrong type (GTP)

Right.
When it asks 'where', select Custom
You will be presented with a list of all existing partitions
Select each, and Delete.
Leaving one large blank space.
Let Windows install to that.