Musicmatch 7.1 or 7.5 not working after going to ie8 cant get ie6

I useing ie8 now musicmatch 7,1 or 7.5 wont let me reinstall i get error 10.1 work but i like 7.1 and 7.5 better what should i do when i try to run ie6 i notice i cant type in outlook express and i cant type in ie just in the address bar. When i unistall ie8 i use revo unistaller and i might unistall some stuff that i did not need to unistall if i go to microsoft website and download ie6 would that do anything to my outlook express 5 email.