The DB/2 Run-Time-Client can be found here:
http://www-1.ibm.com/support/docview.wss?rs=71&uid=swg21255394
Select the 'Runtime Client Installable for Windows' further down the page and download it. 
Clients for other platform (incl. 64-Bit Windows) are also available from that page.