My PC was loaded with Vista Home Premium. The same OS was installed by me on another partition. The second one stopped working after one month for want of activation. My attempts over telephone and on line did not succeed and meanwhile the DVD got damaged too. Then I have purchased Vista Ultimate and installed it on a partition. My system is of Quad core Processor, 4GB memory; 500 GB Hard Disk, partitioned in 8 segments. I would lilke to install Vista Ultimate OS on another partition too. Will it adversely affect my pc? If not please let me know how it can be done and the precautionary measures to be taken by me.