Go to wherever you have your log files saved and double click to open it. Now click on file -> Export Logs -> Tcpdump Format
Save it as 1.cap do the rest of your logs, saving them in sequential order 1.cap, 2.cap, 3.cap etc. Now that you have all of your log files saved in .cap format lets open Aircrack. Open the aircrack folder (wherever you extracted it) then open the Bin folder, now double click Aircrack-ng GUI.exe. Aircrack will open, click the choose button and navigate to where you have your log files saved. To select all of your log files ( saved in .cap format) Hold down CTRL and click each file, Then hit open. Now click launch, Aircrack shows you all of the different BSSID¡¯s that it captured data from and assigns an index number to each one, then it asks you Index number of target network? You want to enter the number of the network you want to crack. Mine is called CrackMePlease so I am selecting 15. Enter the index number and then press enter, if you have enough IV¡¯s then it should give you the WEP key. If not go back and capture more and try again. That¡¯s all