SAP GUI 640 to GUI 710

Guys,

I have SAP GUI 640 in my laptop but I am having problems accessing WAD (BI7.0 Server), so I planned to upgrade my SAP GUI to 710.. Can I driectly install SAP GUI 710 on top of SAP GUI 640 with out uninstalling 640?

Can some one recommend me the best of doing this....

Thanks,

Kumar