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Did you perform the sfc /scannow? Yes/No.
There are many possible causes of your present situation.
If you disconnect from the internet, is the computer still slow? Yes/no?
If you boot up into SafeMode, is the computer still slow? Yes/no?
That's three questions, please answer all three. Ø
Power down your computer. Ø
Power up your computer. Ø
IMMEDIATELY—Start tapping the SPACEBAR Ø
When the Windows Boot Manager
Press the F8
The Advanced Boot Options
screen will appear. Ø
Using the down arrow key, highlight Safe Mode Ø
Press the ENTER
In shorthand, PowerUp | Spacebar
until Windows Boot Manager | F8 | Safe Mode | ENTER