i am assuming you mean 'remote access via activesync'.
one method is to set policy 4097 to 0
from msdn:
The Remote API (RAPI) policy restricts the access of remote applications that are using RAPI to implement ActiveSync operations on mobile devices.
0 ActiveSync service is shut down. RAPI calls are rejected.
1 Full access to ActiveSync is provided. RAPI calls are allowed to process without restrictions.
2 Access to ActiveSync is restricted to the SECROLE_USER_AUTH (User Authenticated) role. RAPI calls are checked against this role mask before they are granted. ( default )
you can do this in several ways:
1) via the CeProcessConfig api ( or the RapiConfig.exe tool )
<wap-provisioningdoc>
<characteristic type="SecurityPolicy">
<parm name="4097" value="0"/>
</characteristic>
</wap-provisioningdoc>
2) in the registry path HKLM\Security\Policies\Policies
lookup the value for 00001001, and set it to 0
a summary of all policy settings can be found here: http://itsme.home.xs4all.nl/projects/xda/smartphone-policies.html