Introduction to Cisco IOS CLI (Command-Line Interface)

Hello Laz,
I went on Cisco’s forum with keyword nvram issues and I solved it like that

Router#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router(config)#config-register 0x2102 
Router(config)#end
Router#show version

At the bottom i got Configuration register is 0x2142 (will be 0x2102 at next reload)
So

Router#reload
System configuration has been modified. Save? [yes/no]: no
Proceed with reload? [confirm]

And…

Router1> enable
Router1# show startup-config

All the data was there !
Thank you Laz for your suggestion.