Hi, Dr. Huang!
I was ultimately able to extract android-x86-7.1-r1.iso and run Android-x86 from my laptop.
I had to use special parameters, like, androidboot.selinux=permissive vmalloc=192M buildvariant=userdebug, nomodeset and xforcevesa. I was inspired by appropriate x-86 info pages and Android's own grub.cfg in /boot folder.
After booting, whenever I tried to install app from Google Play Store, each of them would be downloaded twice, and then stall with an Error Code 963.
The detailed splash screen after the double downloading:
Can't download app
"File Manager" can't be downloaded. Try again, and if the problem
continues, get help troubleshooting (Error Code:963)
I also don't have an option for soft power-off option in the current version of my Android.
Would you kindly advise me as to why is this error code so displayed? The Android is in a Ext3 partition, while my boot folder is on a different partition, along with the main OS for my laptop.