Various sites usually give you semi-accurate info, this is a foolproof method that will work in most cases (only very old or very new hardware may not be supported).
Q) How do I identify my GPU?
A) Get
GPU-z from
here. Just hit the download link on the right and run the exe, no installation needed. The app should show you something like this

I marked the most important bits that you should post here when asking for help
1- The card exact model name
2- The type of VRAM interface
3- The amount of VRAM fitted on the card
4- If you have multiple GPUs, you can select one with this listbox
Q) How do I identify my CPU, motherboard and RAM?
A) Get
CPU-z from
here. There are a few downloads on the right, 32 and 64 bit version depending on your OS and the installer or zipped version. I'll assume you got the installer. So, run the setup, hit next, accept the agreement, next, next, next, deselect the toolbars, next, next, install and when it's done hit finish.
You will get something like this when you run CPU-z

I marked the more important bits
1- The CPU model name and rated frequency
2- The motherboard manufacturer
3- The motherboard model
4- Type of installed memory
5- Amount of system RAM. If you have multiple RAM sticks, you should get a listbox listing all the memory modules you have installed.
Done and done!