Usually, this it's driver-related. Windows 10 won't be able to detect the 2nd monitor if the monitor driver is out of date or faulty. We recommend, rolling back to the previous installed graphics driver and monitor driver if it updated. Otherwise, update your graphics and monitor drivers on the Device Manager. To do so, follow the steps below.
I recently replaced my dead Sceptre X325BV-FMDR with a replacement, Sceptre X322BV-SRR, however, all that seems to be available monitor driver wise is the Generic PnP Monitor. It is functional, but entirely unacceptable for more advanced PC experience, never mind gaming, etc.

I am running about the same monitor on Vista 32-bit and I really didn't need to install any drivers for it. I did move the.inf file to my Vista machine and went into properties and updated the driver for it, but I got no real benifit out of it other than Vista now lists my monitor as a Sceptre.

Sceptre Monitor Drivers E20

Show: Full Specs/Additional configurations

Sceptre Monitor Drivers E24

Active Screen Size : 20'
Aspect Ratio : 16:10 Wide Screen
Display Colors : 16.7M
Response Time : 5ms
Contrast Ratio : 1000:1
Brightness (cd/m²) : 300 nit (cd/m²)
Viewing Angle : 160º (horizontal) 160º (vertical)
Backlight Type : 50,000+ hours
True Resolution : 1680 x 1050
Features
On Screen Display Control (OSD) : Power on/off, OSD (On Screen Display), Contrast, Brightness, Clock, phase, H-Position, V-Position, H-Size, V-Size, Graph/Text Mode Selection, Auto-adjust, Color Temperature, Audio Volume, OSD H-Position, OSD V-Position, Display Mode Detection, Show Firmware Version, and Reset: Basic Setting, Position, Miscellaneous, & All Functions
OSD Supported Languages : English (default), Spanish, French, Dutch
Built-in Stereo Speakers : In-Line Dual Stereo speakers with amplifier (2 Watt /channel)
Base Detachable : Yes
Wall Mountable : Yes
Energy Guide : N/A
Inputs & Outputs
HDMI (# of Ports & Version) : N/A
Supported DVI Signals : 2 MM 24-pin DVI Connector
VGA (# of Ports) : 1.5 M detachable cable 15-pin mini D-Sub VGA Connector
Mechanical Features
Chassis Colors : N/A
Tilt Angles : Yes
Swivel : N/A
Height Adjustment : Yes
Pivot : Yes
Slim Design : Yes
VESA Mount Pattern (mm) : 100mm x 100mm
VESA Mount Screw Size (mm) : N/A
Dimensions
With Stand (inches, W x H x D) : 18.75'(W) x 15.38' (H) x 7.1'(D)
Without Stand (Inches, W x H x D) : N/A
Carton Box Dimension (inches, W x H x D) : 22'(W) x 19.88'(H) x 10.75'(D)
Weight
Net Weight with Stand (lbs) : 18 lbs.
Net Weight without Stand (lbs) : N/A
Gross Weight (lbs) : 25.1 lbs.
Power
Power Range (V, A, Hz) : 80w max 100V to 240V AC @ 50/60 Hz
Power Standby Mode : N/A
Regulations / Certifications
Regulations : N/A
Certifications : UL, FCC-B, EPA