Case Fan Speed

I'm pretty sure I'm alright on this but I want to double check. I just replaced my Case fan,the old one was running at 2300 RPM's the new one is running at 1950 RPM's. When I booted up my computer,( bios) told me to check my fan connects ect. . I went into setup bios and disabled CPU fan speed and PC boots up now with no error and is nice and quiet. I have an HP XL 775,Windows Me,640 of Ram, I'm not a gamer,just use the PC for internet and instant messaging. Was it safe to disable the CPU Fan Speed,I think that was the only way to stop the error at boot up.