Problems with starting BW 7.0 BEx functions

Dear all:

We currently install NetWeaver 2004s on our server. Now we are trying to work with BW7.0 BEx functions. We already have SAP GUI 6.40 patch level 20 and old business explorer for BW 3.5. How can we access new BW 7.0 function , such as Report Designer, query designer , web application designer, etc by invoking Business Explorer. Is there any component we should download and install. Or should we update our GUI?

Now we have facing problems with even start BW 7.0 BEx functions. Any input will be great.

Thank you very much

S.F