DRG NGT VISUAL APCH, PLT ENCTRD DTRTG WX, GOT VECTORS FOR ILS RWY 8 APCH, WAS CLRD FOR APCH AT 0511 CDT. ON FINAL APCH, HE NOTED HIS #1 & #2 ILS'S GIVING ERRATIC LOC & G/S INFO (BUT FUNCTIONING) & THAT HIS LOC COURSE DEVIATION INFO DIDN'T AGREE WITH ADF, BUT HE CONTD APCH. AT 0512, HE HEARD ANOTHER FLT (LNDG ON RWY 14L) RPRT BRKG OUT OF CLDS AT MINS (200' AGL). AT 0513, THE PLT WAS ADZD THE LATEST WX WAS: 200' BRKN, VIS 3 MI. WHILE THE PLT WAS INTERPRETING INSTRUMENTS, THE ACFT BRK OUT OF CLDS & HIT TREES APRX 3/4 MI LEFT OF COURSE, THEN CRASHED & BURNED. ARPT HAD ILS'S FOR RWYS 8 & 26 (WITHDIFFERENT IDENTIFIERS) THAT USED SAME X-MITTER & FREQ FOR THE LOC. THERE WAS EVIDENCE THE X-MITTER WAS SET FOR RWY 26 & THE PLT DIDN'T ID THE SIGNAL. FLT CHK SHOWED ILS WLD HAVE PROVIDED A USABLE SIGNAL IN THAT CONFIGURATION, BUT WITH BACK COURSE (REVERSE) LOC SENSING COMMANDS. TWR CTLR THOUGHT ILS WAS SET FOR RWY 8, BUT DIDN'T RECALL CHGG IT FM RWY 26. ATISHADN'T BEEN UPDATED SINCE 0011 CDT. 0529 WX: 100' OVC, 3/4 MI VIS WITH FOG (1/4 MI VIS AT TWR). ATCT SUPV NOT IN TWR CAB