Using the Control centre, just disable your side screens so you only have the one in the middle working. SAVE that as a PRESET.
If you're in eyefinity mode right now, open VECC and save the current eyefinity setup as a PRESET too before disabling as above.
Now, when you know you've got a game that only uses one screen activate that PRESET beforehand.
#1: FX-6350, Antec Kuhler 920, MSI 970 Gaming, Asus 5870/V2, ASUS Xonar D2X, GSkill (F3-14900cl9d-8gbxl), Antec Truepower New 750, Arc Midi, Win8.1pro x64
#2: MSI A88X-G45, AMD A10-7850K, IGP, AMD 2x4GB 2133 (R938G2130UK), Antec 750 True, 128GB Sandisk SSD, WD Black 1TB, Win8.1pro x64
#3: Athlon 64 X2 4200+, AGP 1950pro, Audigy 2, Asus A8V-D, 2gig ram, Enermax 465P, Antec900case. Now on Win8.1pro cat 10.2