Hello my name is ***** ***** can actually get the windows installation disk by contacting dell and asking for the original hard copy recovery software for your machine. They would then provide you with the windows install disk which would be windows 7 and the drivers and applications disk.
You would need to load the windows disk into the cd drive restart the machine and push f12 when you see the dell logo and then choose the cd drive. They you should be able to let the disk load and once loaded instead of choosing to install you click on repair your computer. Then choose startup repair. If that repair fails you would need to install fresh especially if there is too much damage during the boot process. But that should fix the problem.
You would actually have to call dell to get this disk, give me a moment I will give you the number to dell.
1-***-***-**** that is the number you would need to call.