Remember how I pleaded with you a dozen times to follow the steps in
Clean Reinstall - Factory OEM Windows 7 for handling drivers in Win7, how you ignored this and merrily went on to install every driver on the Dell Downloads page, ignoring whether Win7 had delivered another driver it wanted?
Well look at the reason your Startup cannot now be repaired in the last, fatal Problem Signature 7!
Work through these steps which provide everything possible for
Troubleshooting Windows 7 Failure to Start leading up to if necessary a Clean Reinstall, this time following the steps to get a perfect install. Wipe the SSD first with
Diskpart Clean Command; disable the HDD in BIOS if possible.
Or maybe there is a Restore Point to run from
System Recovery Options before you did your own thing and wasted our time and yours.