This is the new motherboard support for pentium 4/800,so must support large disk to.

Check and make sure that both drivers are plugged in at the correct location on the cable and be sure the master slave jumpers are set correct. If all is correct there then run Partition Magic or another disk program and set the partitions that way. Then go in disk managment and double check.

Thanks
Dudelive

Thanx for all yours answers,but I have enough work with this second drive(slave)!
I try almost everything what I know,but always fail when I try to format drive,so I just set this disk to master and install windows again.Maybae something not work correct when I have this drive set as slave.When I set jumpers to master and second disk to slave everything work without any problem.
I really don't know why not work in slave mode.Now I have this disk 80gb and second one 40gb.I like to have second disk larger,becouse I need it for video editing,but o.k.,only work a litle slower,becouse it's half large.

Cheers!

Are the drives different brands? I remember having trouble mixing Conner and Maxtor or Conner and WD drives, each one wanted to be Master. I ended up getting rid of the Conner and getting another Maxtor. After that, all worked fine. Don't know if this problem stilll happens with newer drives, these were 1 or 2GB drives I was having problems with. You also might try another IDE cable, it may be bad.