services greyed out in windows 7

Hi

I am hoping somebody can assist, I have for many years disbaled certain services to ensure my pc is running at maximum speed without many overheads. for some reason i am unable to do this in windows 7. if i go into the management console i can normally disable certain services but for some reason its all greyed out.

startup type-greyed out
start-greyed out
stop-greyed out
resume-greyed out


How can i get round this? The account i use to log on has administrive credentials.

Kind Regards
Richard