router and modem problem

hi to all, and happy new year too.
i was wondering if anyone could help me with this little problem that i am having with my wireless.

my provider told me that i need a router to communicate with the wireless router that i have in my house, they said that it wont work if there is a modem connected to the router, only one router to another, this makes no sense to me, but then again, who am i.
so i got the two reouters, but there were major problems and i managed to convert the router they provided me with into a modem through cmd prompt. however, this is an unreliable and tempermantal fix to the problem.
can anyone please tell me what i am supposed to do, do i ask for a modem off my providers, or are they correct and i should keep this router and continue with the problems????

 

ok well...look...if you want a wireless router like...with connectrion to ur modem i have a linksys befw11s4 v4 and its a wireless with 4 wire plugs so...maybe try that i have it wall to router to modem to my comp to dads w/ cords andi coudl go wireless if i wana but i dont want 2...router was only 40 bucks w/ 10 rebate ormayb itw as 30 bucks...go to radioshack they got a helluva deal on it