Yes the 5450 is a very weak card. It is only as good as the Intel integrated HD 3000 (IGP) of older processors.
Might as well remove the 5450.
http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107-7.html
In this case, there is an easy way to tell if your IGP is enabled. Simply remove the 5450 and connect your monitor to the video port of the motherboard (it should have VGA or DVI ports)
If you are able to go into Windows normally, it means the IGP is enabled and doing its job. Problem solved.
If it is not, you will have to insert the card and enter the BIOS to turn the IGP on. To enter the BIOS, mash the Delete button when booting up.
I don't know where in the BIOS you will find the setting, but it should appear to be something like "Integrated Graphics" or "IGP".