I am attempting to install Intel HD 4000 graphics card then it says this computer does not meet minimum requirements for installing software on my
DELL OPTIPLEX 745
Windows XP Professional 2002
Service Pack 2
Pentium(R) D CPU 3.00GHz
2.99GHz, 0.99GB Of RAM
The video controller in your system is actually the Intel(R) Q965 Express Chipset controller as per DELL's web site. That is the reason why you may not install the driver for the Intel® HD Graphics 4000, as it's a different product.
The latest driver we provide for the video controller in your system is posted here: