windows 7 installation problem

[parshuram rathod]

i want install windows 7 in dell optiplex 745 but not installation pls help us.

 

[avenseth12]

What operating system do you currently have? Have you purchased a retail or OEM version of Windows 7?

 

[parshuram rathod]

yes i have OEM CD, But when i put in the CD in CD ROM and than display shown "Press any key..........),
And then Boot my CD all format C Drive and than display shown Expending File 56, and than automatically screen blue......
pls how can i solve this problem.