What you tecno adviser means is to format the drive first,basically wiping it clean.
You will lose everything if not backed up.
have you looked to see if you have a hidden partition containing a restore/recovery program.
Normally tapping F11 or F10 on startup will show the partition if it exists.
Also check disc management:
Start / Right click my computer / Manage / Disc management look to see if a recovery partition exists.