If I understand the question. Open the graphic in a graphics editing program such as Paint, Gimp and many others to numerous to mention. There will be a tool to add a text box. After adding the text you can save it to a new file conserving the original or just write over the original on the save.
My Computer
Computer Manufacturer/Model Number
BGC (Bob's Garage Crew)
OS
win 7 X64 Ultimate SP1
CPU
I3770K
Motherboard
Asus P8Z77-V Deluxe
Memory
G Skill F3-14900CL9-4GBXL x 4
Graphics Card(s)
NVIDIA GeForce GTX670 + Intel 4000
Sound Card
Realtek HD 5.1 (MOB)
Monitor(s) Displays
Asus VW224T (1)
Screen Resolution
1920 x 1080
Hard Drives
SATA Corsair Force GT 2.5" 180GB (System) Sata 3
OCZ Vertex3 120GB
OCZ Vertex 2 120GB 2.5" SATA II
ST31000524AS 1000.2GB
WD15EARS (External)
Or, if you're referring to text and images in a Word page, you can do it several ways, i.e. by using the Watermark options in the Page Layout section of the Ribbon or by using the graphics options in the Insert section.
My Computer
Computer Manufacturer/Model Number
HP Pavillion dv5t (generation 1)
OS
Vista 64 bit and 32 bit (SP2)
CPU
Intel(R) Core(TM)2 Duo Processor T9400 (2.53 GHz
Memory
4GB DDR2 System Memory (2 Dimm)
Graphics Card(s)
512 MB NVIDIA GeForce 9600M GT
Monitor(s) Displays
15.4" diagonal WSXGA+ High-Definition HP BrightView Widescre
Screen Resolution
1680 x 1050
Hard Drives
320GB 5400RPM SATA Hard Drive with HP ProtectSmart Hard Drive Protection
Keyboard
Built-in HP
Mouse
Built in - Synaptics TouchPad V6.5 on PS/2 Port
Internet Speed
Max
Other Info
~ Intel Next-Gen Wireless-N Mini-card w/Bluetooth ~ Blu-Ray ROM DVD+/-R/RW ~ Integ. HDTV Hybrid Tuner ~ 12 Cell Battery ~ MS Office (Home Premium) 2007 ~