; you have to allocate enough memory for the string in the ".data?" ; section:
.data?
szBuff db 256 dup(?)
; then when you call StdIn it will write user input into szBuff


.386
.model...

; you mean storing it even after program close?
; then : In Registry (RegOpenKeyEx, RegQueryValueEx, RegSetValueEx ...) , In a File ( CreateFile, WriteFile, ReadFile ...), In .ini File ( you can...