Oracle Database 10.2.0.5.0 Client software is not available for download on https://edelivery.oracle.com.
Please open an service request on My Oracle Support and ask for an media or a temporary link for the download.
Pl identify exact versions of "10gR2" and Windows 7. The only certified combination is 10.2.0.5 on Win 7 Professional or higher. Home version of Windows is not supported. Using uncertifed combinations will result in the software not working as advertised.
See http://docs.oracle.com/cd/B19306_01/relnotes.102/b14264/toc.htm#CIHCFAGA (see Step 4 - the 10.2.0.5 patch can only be downloaded by paying support customers at https://support.oracle.com)
Since 10gR2 is now out of premier support, publicly available download links have been removed. If you have a support contract with Oracle, pl open an SR. If not, you will have to download one of the publicly available versions.
I too facing same problem. Since exp utility is not back-ward compatible. I was receiving error ORA-904 POLTYP invalid identifier.
I went to my oracle support could not find the patch for bug id Bug 756835.
We would need to download Oracle 10g client for this purpose atleast.