Right!
HP.com's website for your product is this:
**Clicky**Hardware
Product Name g6-1b39wm
Product Number LW363UA#ABA
Microprocessor 1.6GHz VISION E2 Technology from AMD with AMD Dual-Core E-350 Accelerated Processor
Microprocessor Cache 1MB L2 Cache
Memory 4GB DDR3 System Memory (2 DIMM)
Memory Max Maximum supported = 8GB ((((((((((((((((((((((((((((THIS IS THE VALUE YOU'RE LOOKING FOR - Compare this value with the value your system has)
Video Graphics AMD Radeon HD 6310 Discrete-Class Graphics
Video Memory Up to 1973MB
Hard Drive 500GB (5400RPM)
Multimedia Drive SuperMulti DVD Burner
Display 15.6" diagonal High-Definition HP BrightView LED Display (1366 x 768)
Network Card Integrated 10/100 Ethernet LAN
Wireless Connectivity
802.11b/g/n WLAN
Sound
SRS Premium Sound with Altec Lansing speakers
Keyboard Full-Size Keyboard
Pointing Device Touch Pad with Multi-Gesture Support and On/Off Button
External Ports
Digital Media Card Reader for Secure Digital and Multimedia cards
3 Universal Serial Bus (USB) 2.0
1 HDMI
1 VGA (15-pin)
1 RJ -45 (LAN)
1 Headphone-out
1 Microphone-in
Dimensions 14.72" (L)x 9.65" (W) x 1.20" (min H)/1.43" (max H)
Weight 5.22 lbs
Security
Kensington MicroSaver lock slot
Power-on password
Accepts 3rd party security lock devices
Power
65W AC Adapter
6-Cell 47WHr Lithium-Ion Battery
What's In The Box HP Webcam with integrated digital microphone
Software
Operating System:
Genuine Windows 7 Home Premium
Security and Support:
Free 60-day Norton Internet Security 2011 Subscription
HP Support Assistant; HP Power Manager
HP Setup Manager; HP Recovery Manager
LoJack Theft Protection (Link In Start Menu)
Multimedia:
HP Games powered by WildTangent: includes 5 free games valued at $100 MSRP.
Cyberlink PowerDVD 9 (41)
Cyberlink YouCam BE
HP Music Store powered by Rhapsody (15c); HP Movie Store powered by RoxioNow (15d)
Snapfish Picture Mover; eBay (Link on desktop)
Walmart Photo Center
Productivity and Finance:
Microsoft Office 2010 preloaded (purchase of a Product Key required to activate a full Office 2010 suite) (34)
Windows Live Essentials 2011: Windows Live Mail; Windows Live Messenger; Windows Live Photo Gallery; Windows Live Movie Maker; Windows Live Writer; Windows Live Mesh
Internet Solutions:
Internet Explorer 9
HP Connection Manager
Bing Bar
Blio eReader application with full color: includes 4 free digital books valued at $75 MSRP.
So yeah if the Memory MAX is 8GB and you have 4GB installed, and it has two DIMM slots, then it's likely that you either have one 4GB DIMM Chip (unlikely) or you have two 2GB DIMM Chips (probably more likely).
In order to upgrade to the maximum RAM, which is 8GB, you have to purchase two Notebook 4GB DDR3 Chips. Install each on each slot, and when you turn the system on, Win7 will notice your extra RAM. It's awesome to have 8GB of RAM.