I bought a new disk that I planned to use to make a winxp computer into a win 7 computer. The system originally consistent of a hd containing the os and some additional storage. Additionally there were two other hds. I installed the win 7 system in the new disk with the other disks not connected. Everything worked well. I then connected the other disks, one of which still contained a working winxp system. The system booted ok and seemed to work. Next time I booted the win 7 disk, the winxp splash screen came up and the system would not boot on win 7. I thought to start over by using killdisk on the new win 7 installation. The DOS killdisk is not recognized. In addition, it will not now boot on win 7. When I put a partitioning ap on the win dxp disk, the disk containing the win 7 files is not recognized at all. How can I get access to the win 7 disk to erase it or how can I get the win 7 installation os recognized so that it will booAny thoughts would be appreciated.