I'm in emergency so I've to type it short and simple. Just now, I downloaded the iso file of Ubuntu Alternate AMD64 and I extract it to partition D (Windows is installed in partition C). After that, I reboot. It went into the Ubuntu installation setup without problem but when it start to format, it says CD source not available or something like that because I didn't mention it that time. Therefore, I reboot again but it takes me to the Ubuntu installation setup again, I reboot and I place the Windows 7 Home Premium disc into my DVD drive and boot from it. I went in to delete the partition D and never extended partition C and kept the unallocated space, I reboot again. It says "Missing Operating System" and boot from the Windows disc again, I click on Startup Repair and it took about 20 minutes and kept saying "Attempting repairs...". Please help me, if you need any of my specs please reply, thanks again. And yeah, some files are backup but some programs and big sized videos are not and for the programs, I don't want to lose the saved games and for the videos I don't want to download them again because my internet speed is only 512Kilobits/s on here.