Why did you post to the Spanish language topic folder of the forum instead of the General topic?
If you really want to remove OneCare and use something else, go ahead and uninstall it. Use the cleanup tool, if you want to be sure all remnants are gone - http://forums.microsoft.com/WindowsOneCare/ShowPost.aspx?PostID=828910&SiteID=2
The CD ROM problem occurs with the removal of many different programs that include burning capabilities. See this link for a utility to restore the drive to Explorer on your PC:
Restore CD/DVD Drives to Explorer
I'll also note that if you believe that OneCare is slowing down your PC and your PC meets at least the minimum system requirements, the problem is not likely OneCare, but a conflict with other active security software that you have running on the PC.
-steve