iTunes not recognizing ipod touch

Hope someone can help, I have a Dell Inspiron laptop running service pack 2, with 2.0 usb drivers...I got a touch for xmas and my itunes sometimes recognizes it, sometimes doesn't, when it does recognize it, it takes forever to sync (15 hours for 1100 songs)...So today I tried to plug my touch into my computer and it won't even open itunes...my computer recognizes that it's there under device manager, but itunes doesn't, I plug in my 30gb ipod video, and it syncs right up, no problems....I have 7.5 itunes and have uninstalled it and reinstalled it several times with no luck...could it be a memory/hard drive issue, my laptop is pretty full...I know it's not the touch because it works with other computers...HELP!!