Help with Windows ME

Hello all. I am trying to fix an old computer of mine for my son to use. It is an old Compaq with Windows ME. Problem is I can’t install any downloads of any kind. Can’t open any file on my pc. Everytime I try to open a file, I get the open with dialog box. I click on say Internet Explorer and ok and nothing happens. No new window, no bars, no box, no nothing.I tried to do a system restore, but I cant do that either. It keeps asking me what I want to open this with. I can get on the internet and download and surf, but I cant install any downloads after downloading. Don’t have a disk for this cuz its old. What do I do. Im really stumped. Any help at all would be very much appreciated.