:sarc: Up until version 77 (I believe) there was a way to disable firefox's e10s. The multi instances seriously slow down my pc. Then they did away with making changes in aboutconfig that used to work. The last "fix" I have found was from about a year ago, suggesting to add an environment variable. It worked for some folks but it never worked for me. I haven't been able to find anything else anywhere regarding disabling e10s. I am seriously considering using an older version of FF that will allow me to disable e10s, or even go to another browser. Anyone out there know of a new trick to disable e10s in FF? 
Running win 7 pro with version 82 FF

Running win 7 pro with version 82 FF
My Computer
At a glance
Operating System : Windows 7 Professional Pro...Processor : Intel Core 2 Duo E6400 @ 2133 MHzPhysical Memory : 8 GBVideo Card : Intel(R) Q965/Q963 Express Chips...
- Computer type
- PC/Desktop
- Computer Manufacturer/Model Number
- Dell Optiplex 745
- OS
- Operating System : Windows 7 Professional Professional Media Center 6.01.7601 Service Pack 1 (64-bit
- CPU
- Processor : Intel Core 2 Duo E6400 @ 2133 MHz
- Motherboard
- Mainboard : Dell 0HP962
- Memory
- Physical Memory : 8 GB
- Graphics Card(s)
- Video Card : Intel(R) Q965/Q963 Express Chipset Family
- Sound Card
- Device Audio : Dell Computer 82801H (ICH8 Family) HD Audio C
- Monitor(s) Displays
- Monitor Type : Dell Computer DELL IN1910N - 19 inches
- Screen Resolution
- Current Display : 1366x768 pixels at 60 Hz in True Colors (3
- Hard Drives
- Hard Disk : Western Digital WD2500AAKX-00ERMA0 ATA Device (250GB)
Hard Disk : TOSHIBA External USB 3.0 (500GB)
Drive : SanDisk Cruzer Glide USB Device
- Keyboard
- Type of keyboard : USB Input Device
- Mouse
- Type ofmouse : USB Input Device
- Internet Speed
- +- 100bps (supposedly)
- Antivirus
- Zonealarm
- Browser
- Firefox
- Other Info
- Chipset : Intel Q963
DVD-Rom Drive : Toshiba-Samsung CDRWDVD TS-H493B
Network Card : Broadcom NetXtreme BCM5754 Gigabit Ethernet PCIe
DirectX : Version 11.00
Windows Performance Index : 3.4 on 7.9
Back to the drawing board?...