Hi Double R59. Welcome to BleepingComputer
You can use any of IE 32-bit or 64-bit.
64 bit is newer, faster version and uses memory more efficiently on a 64-bit Windows based system. But the problem is some activex components were written using 32-bit code, so they may cause problem in 64-bit IE. Simialrly, newer 64-bit ActiveX components, toolbars, add-ons etc will not work in the 32-bit version of IE. Also some sites are more compatible with 32bit IE. So Microsoft has included both 32 and 64 bit versions of IE. If you find problems in 64bit use 32bit, and vice-versa
More information : http://support.microsoft.com/kb/896457
Edited by Romeo29, 13 September 2009 - 03:59 PM.