Can my computer run 64 bit?

A long time back I installed Windows 7 on my HP Pavilion p6130a Desktop PC, at the time upgrade adviser said I should install 32 bit, which I did. Now that I've filled my hard drive, I've bought a larger one and was thinking of making it the primary drive and reinstalling my operating system onto it.
I'm wanting to install 64 bit, but I'm confused as to why advisor said I need 32 bit. Does this mean my motherboard is unable to run 64 bit?
This is the computer I have,
http://h20566.www2.hp.com/portal/site/hpsc/template.PAGE/public/kb/docDisplay?javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&javax.portlet.prp_ba847bafb2a2d782fcbb0710b053ce01=wsrp-navigationalState%3DdocId%253Demr_na-c01742894-29%257CdocLocale%253D%257CcalledBy%253D&javax.portlet.tpst=ba847bafb2a2d782fcbb0710b053ce01&ac.admitted=1409560022945.876444892.199480143
I've long ago upgraded to 4GB ram, and more recently put a more powerful psu and a R7 250 gpu which it seems to be able to run to full potential. However I would like it to be a 64 bit machine.
 
YoU are okk with win 7 64 bit.

1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor

1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)

16 GB available hard disk space (32-bit) or 20 GB (64-bit)

DirectX 9 graphics device with WDDM 1.0 or higher driver