But if I had run into a problem, I would've restored from a backup. If you have an option to restore to factory settings, you can do that. If not, you'll need to contact Dell to get the necessary discs for a small fee.
When you've gotten your system back like you want it, I urge you to get yourself an external hard drive and a good 3rd party backup program. You can set it up to do everything automagically at the time and frequency of your choice. 1 TB external hard drives are about $50 these days and a really good FREE backup program is the Easeus Todo Backup Free. That can save you a lot of time and frustration the next time something like this happens. Sooner or later it happens to all computers for one reason or another.

Good luck.