Slow boot time after BSOD

Try loading in "Safe Mode" and see if you still get the horrible slowness. If not, I would hazard a guess that there is something on the computer that your malware program didn't detect. You may want to run antivirus software as well as a few other programs for ad ware, etc. "Safe Mode" should also allow you ways to assist in finding the problem.

How to enter "Safe Mode" when booting the computer.

In Windows 8 and 10 ...

As your computer restarts, press F8 (possibly a few times) to enter "Safe Mode"

a. Press the "F4" key to Enable "Safe Mode".
(The computer will then start in "Safe Mode" with a minimal set of drivers and services.)

b. Press the "F5" key to Enable "Safe Mode" with Networking.
( Once "Safe Mode" with Networking starts, Windows is in Safe Mode, with additional network and services for accessing the Internet and other computers on your network.)

c. Press the "F6" key to Enable "Safe Mode" with Command Prompt.
(In "Safe Mode" with "Command Prompt" starts Windows in Safe Mode, with a Command Prompt window instead of the Windows interface. This option is mostly only used by IT professionals.)

Now sign in to the computer with your account name and password. (If you have one set.) When you are finished troubleshooting, you can exit "Safe Mode" restarting your computer.