Yes it is possible, refer to the link below:http://www.pctools.com/guides/registry/detail/855/
Basically, there is an amount of bandwidth which is reserved for QoS traffic - one of the client / protocol / service units that is configured on every network connection. It reserves space for this type of traffic if you have the service / protocol installed. Hence if you are working on a WiFi connection which is rated at 54 Mbps (that's megabits per second, not megabytes per second - which would be written MBps), you may see traffic rated at a lower speed due to reserved bandwidth.
This is of course, only one of multiple reasons for which you may see reduced bandwidth, but most likely is an effect which you are witnessing.
In my experience i have seen different bandwidths reported on the same network. For example, when i use my alternate desktop machine, which has a PCI WLAN card and a USB N1 WLAN adapter, connecting to a Linksys WRT54G wireless router - i know that by default the WRT54G is rated at 54 Mbps on a wireless a/b/g network. However, my PCI WLAN card will indicate connection at 36 Mbps whereas my USB N1 adapter will indicate connection at 54 Mbps.
Distance, interference, signal attenuation and signal frequency will also play a role in the connection speed. But using the link above, you can tweak the QoS traffic scheduler to maximize your usable bandwidth - as long as you are absolutely sure you will not need to utilize that service or protocol.
I suggest that you leave the connection settings as is; i don't think you are sacrificing too much if its only 2 Mbps overall.