Sorted it myself. Code as below.
Select Top 1000000 tblAssets.AssetName,
tblAssets.IPAddress,
tblADComputers.OU,
tblADComputers.Lastchanged,
tblAssets.Username,
tblAssets.Lastseen,
tblAssets.Lasttried,
tblADComputers.AssetID
From tblADComputers
Inner Join tblAssets On tblAssets.AssetID = dbo.tblADComputers.AssetID
Where
(tblADComputers.OU =
'OU=Win7,OU=Computers,OU=UK,DC=Some,DC=company,DC=com')) Or
(tblADComputers.OU =
'OU=Win8,OU=Computers,OU=UK,DC=Some,DC=company,DC=com') Or
(tblADComputers.OU =
'OU=Mac,OU=Computers,OU=UK,DC=Some,DC=company,DC=com') Or
(tblADComputers.OU =
'OU=Misc,OU=Computers,OU=UK,DC=Some,DC=company,DC=com') Or
(tblADComputers.OU =
'OU=Tablets,OU=Computers,OU=UK,DC=Some,DC=company,DC=com') Or
(tblADComputers.OU =
'OU=Test,OU=Win7,OU=Computers,OU=UK,DC=Some,DC=company,DC=com')) Or
(tblADComputers.OU =
'OU=RTest,OU=Win7,OU=Computers,OU=UK,DC=Some,DC=company,DC=com')) Or
(tblADComputers.OU =
'OU=Rooms,OU=Win7,OU=Computers,OU=FR,DC=Some,DC=company,DC=com') Or
(tblADComputers.OU =
'OU=Offline,OU=Win7,OU=Computers,OU=FR,DC=Some,DC=company,DC=com')) Or
(tblADComputers.OU =
'OU=Win7,OU=Computers,OU=FR,DC=Some,DC=company,DC=com')) Or
(tblADComputers.OU =
'OU=Win7,OU=Computers,OU=US,DC=Some,DC=company,DC=com')) Or
(tblADComputers.OU =
'OU=Rooms,OU=Win7,OU=Computers,OU=US,DC=Some,DC=company,DC=com') Or
(tblADComputers.OU =
'OU=1234,OU=Win7,OU=Computers,OU=US,DC=Some,DC=company,DC=com'))
Order By tblAssets.AssetName