screen ratio issue with guest additions installation

[virtualboxuser092846]

When I install guest additions, the version of the software and the extension pack on my vm guest OS Windows Server 2008 SP2, the screen ratio automatically gets reduced and cant be altered, as you can see in this image, can you give me a fix for this issue?

2.PNG (73.62 KiB) Viewed 1688 times

[virtualboxuser092846]

01.PNG (51.18 KiB) Viewed 1602 times

anybody? it even distorts logos...what could possibly be wrong?