Arduino Uno / Atmega 328

I'm new to Arduino's world;
I got my Arduino Uno to work ok and made some basic exemples... I have made my first program and load it in and it was funcionning but when I have changed the Atmega 328 with a new "328 PU" recently purchased from Digikey, I ca'nt get this guy to work; here is wath it tells me:

Arduino : 1.6.6 (Windows 7), Carte : "Arduino/Genuino Uno"

Le croquis utilise 1 174 octets (3%) de l'espace de stockage de programmes. Le maximum est de 32 256 octets.
Les variables globales utilisent 9 octets (0%) de mémoire dynamique, ce qui laisse 2 039 octets pour les variables locales. Le maximum est de 2 048 octets.
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x91
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x91
Problème de téléversement vers la carte. Voir http://www.arduino.cc/en/Guide/Troubleshooting#upload pour suggestions.

Ce rapport contiendrait plus d'informations si l'option
"Montrer les informations de sortie pendant la compilation"
était activée dans Fichier > Préférences.
What's up doctor?
oldSchoolBob

Has the chip got a bootloader on it ?

When you bought it, did it say it came with the Arduino boot loader already loaded? If not, there is an option in the IDE to burn the boot loader to the chip.

Have you got a second Uno? You can see if the first one has a bootloader with it.

Detect Chip Signatures

If you bought it direct from Digikey it may well not have a bootloader.

To Delta_G: No it did'nt say anything
To Nick: I'm looking into your suggestions...
Shall feedback!
Thank's to all
oldSchoolBob

I read the "Using an Arduino as an AVR ISP" from Arduino web site; I wired up an external Atmega328 on a board w/ 16Mhz crystal+ caps, the 10K R is installed from 328 pin1 (reset) to +5V, I've uploaded the ArduinoISP code (note that my version is Arduino 1.6.6) still I looked up if I could find that "heartbeat()" in case the modif (delay(40) to delay(20) would apply (Not!) The upload was done with yhe auxiliary 328 not tied to the Uno. The upload went OK.
When I trie to use the feature to burn-in the up-loader, I always end-up with messages telling me that it cannot communicate.
Note: The COM port stays always to COM20, I tried different ways from the suggestions from the site but always en-up with same situation
(????)
Regards
oldSchoolBob