increasing wireless pci card transmission strength

As my title suggests, im looking to boost my wireless pci card strength on my pc so i dont have to buy a wireless repeater or so on.
Just wondering if there is any programg out there like this?
Thanks

 

Not really any software for this that I know of unless you want to go to an open source firmware that may be available for your router.

Check your NIC configuration and make sure the power is at 100%.
Try different channels.
Change location of PC or router. Mainly see if you can get a better line of sight if possible or make sure you are not transmitting "through" heavy furniture, metal objects, thick walls.
Some routers have longer antennas available for a more powerful signal (or actually less signal loss) in transmitting.