extending wireless range of huawei quidway wa1003A

[saturnine]

HIim a newbie hereim using the bsnl-provided Huawei quidway WA1003A router/modemit is installed alongside a desktop PC in my home officeinternet works fine if im in the same room with above-average speedsinternet sharing is enabledi can connect both the desktop and laptop at the same time however on leaving the room with its door shut i lose the signalor on rare occasions receive an extremely weak & unusable oneid like to be able access the internet in my home as well. there are a couple of doors and walls in between the two locationsim using a Dell inspiron6400 with vista Are there any recommended methods to improve the signal strengthi would not want to change the present location of the router After a bit of reading, as i understand it, there are 'range extenders' availableD-link being a company mentioned somewhereNot being too technologically proficient im pretty confused in this matter Can anyone recommend any specific models which would work with the wa1003a? Do i need some other hardware instead?Any tried and tested 'tweaks' that i may apply to my existing setup to achieve the same result thanks in advance for your adviceregardsaditya