Running Office 2010 64-bit provides the following advantages:
· Ability to utilize additional memory.
· Excel 2010 can load much larger workbooks. Excel 2010 made updates to use 64
-bit memory addressing to break out of the 2-GB addressable memory boundary tha
t limits 32-bit applications.
· Microsoft Project 2010 provides improved capacity, especially when you are d
ealing with many subprojects to a large project.
· Enhanced default security protections through Hardware Data Execution Preven
The following issues might affect compatibility.
Microsoft Access MDE/ADE/ACCDE files
Databases that have had their source code removed (such as .mde, .ade, and .acc
de files) cannot be moved between 32-bit and 64-bit editions of Office 2010. Su
ch databases that are created by using 32-bit Office (any version) can be used
only with 32-bit Office, and a database that is created on 64-bit Office can
be used only on 64-bit Office.
ActiveX controls and COM Add-ins
ActiveX controls and add-in (COM) DLLs (dynamic link libraries) that were writt
en for 32-bit Office will not work in a 64-bit process. As a result, Office 201
0 64-bit solutions that try to load 32-bit ActiveX controls or DLLs will not wo
rk. 64-bit Office 2010 installations will only run 64-bit controls. Computers c
an have 64-bit and 32-bit controls installed and Microsoft Office 2010 64-bit c
an only run the 64-bit versions of the controls. The workaround for resolving t
hese issues is to obtain 64-bit compatible controls and add-ins or to install O
ffice 2010 32-bit (WOW).
In addition to controls that load into Office applications, there are also Web-
based solutions that use ActiveX controls in Microsoft Internet Explorer. Offic
e 2010 64-bit editions install some Office 32-bit client-side controls for supp
orting solutions in a 32-bit browser (the default browser on current 64-bit Win
dows systems). The Edit in Datasheet View functionality is not supported if you
install Office 2010 64-bit clients. The Datasheet View functionality is availa
ble if you install Office 2010 32-bit.
The following issues might occur if there is not a match between the bitness of
Office 2010 and registered applications:
· An OLE server may not instantiate in place and may fail to open if the appli
cation registered is not the same bitness as the version of Office installed. F
or example, if your OLE Server application is 32-bit and the version of Office
installed is 64-bit.
· Inserting an object into an Office 2010 application document may fail in cro
ss-bitness scenarios. For example if you insert a 32-bit object in a 64-bit Off
ice 2010 application document.
There are differences between the 32-bit and 64-bit Graphics Device Interface (
GDI) that might have performance implications because of the lack of MMX suppor
t on 64-bit. Intel's MMX technology is an
extension of the Intel architecture (IA) instruction set. The technology uses a
single-instruction, multiple-data (SIMD) technique to speed up multimedia and
communications software by processing data elements in parallel.
Visual Basic for Applications (VBA)
VBA code that uses the Declare statement to access the Windows application prog
ramming interface (API) or other DLL entry points will see differences between
32-bit and 64-bit versions. The Declare statement must be updated with the PtrS
afe attribute after inputs and outputs to the API have been reviewed and update
d. Declare statements will not work in 64-bit VBA without the PtrSafe attribute
. New data types are added to 64-bit Office 2010 VBA: LongLong and LongPtr.