Well after reformating my hard drive and then installing Windows ME on my Compaq 7151WM. I went to control panel and then to modems and went to autodetect for my modem and it didnt find it...so right now i am stuck, my modem is a 56K ITU V.90 Modem, which i got off the label on the side of the computer:-D

Do you know what brand it is? Can you remember what it said when you were running 98? Without a brand name its hard.
Go into control panel/system and see if anything listed there has a yellow question mark. Its probably the modem if there is.
Go back into control panel/add new hardware and run it. When windows comes up with the option 'do you want windows to find it' select no and a hardware list should come up. Choose modem, then show list and see if yours is on it. If so select it and continue. It should then set it up. If its not in the list you will have to find a driver for it on the net, repeat the process and click have disk. browse to where you saved the driver and click ok.