Thanks but I had tried that already and it didn't work, it only found the first variable, I even swapped them to confirm this.
I think I'll go with using the above single variable and add extra countifs with a "+" in between to get the result I need. seems to work ok.
=COUNTIFS(Netc!C4:C1008,"open",Netc!D4
1008 ,"PC") +
COUNTIFS(Netc!C4:C1008,"waiting parts",Netc!D4
1008 ,"PC")