help with browser downloading

[urie]

can any one help i can't download any rar or zip files they are opening up in browser and are viewing like text files something has changed on my system was using firefox and maxthon even Iexplore it's happening with all off them ,

had this problem once before can't remember how i fixed it

here is a sample of what it looks like

PK   uv?2Qº7ßr   '     dac.nfoíYÍr¹¾«JïÐ{t?DýØ»ë&K´Ký°HJJrH?K?¤?%?B?¬õ>/?=躰f𺥿nÌ?4);UÞSÊ°<ä?Ý?¯??"24SJúBñõ§ó¾yXábVWf@¤ÒâKáµ=ÊL?Pù´Îò_¬óèUX@£æ9?:@?³?),0?d0?ÞY?pk±Ï?ò.ªh\il¼hsí ??%0??8l`*w3ÄGË??o%®<? ?i ¹Í¸k°?g-ãL4?kÜE'l??ga£áÁÔÕ`1¬¡àkIè,?¢¿?ÏÕ½?kPû ãV\¯W¨êA?«?q¥£?
ÏßÐXácä¹5"d¨*ØÄÂ{S?°oF?Çäë?°?1µ%YË1,ØyÀ95³²ð?í?]Å?m?&ÓÇxNi?Ì??R8KbÛ$uHPÉ?À-ØUÀò3¶t*?*\rÇPÏ
??é`I=Fø¥P?!&¤ 3 _É

[urie]

Edit this is only happening on one site

[N1K]

Edit this is only happening on one site

The problem is obviously in that web site..