Can you please help me out in Installing pgRouting in Windows 7 64-bit version.
I have been trying it for days. Since I am completely new to this please provide me the initial requirements and steps in installing pgRouting.
Do you mean that you want to run pgRouting on Windows 7 64-bit OS?
If so, try as follows.
If you want to run pgRouting as 64-bit mode (on PostgreSQL 9.1 (Win x86_64)),
AFAIK, pgRouting have not supported Windows 64-bit mode yet.
P.S. Short update. Now you can run 64-bit version of pgRouting on Win7 as well - pgRouting binaries built in 64-bit mode could be found by the provided above link on githun (thanks to Sanak!). It was checked with Postgres 9.1/PostGIS 2.0
Your question was just discussed on the pgRouting mailing list: http://lists.osgeo.org/pipermail/pgrouting-users/2012-May/001142.html
Currently there are no Windows 64bit binaries available, mainly because there were no 64bit Windows binaries available for PostGIS 1.5. Instead most people used 32Bit versions of PostgreSQL/PostGIS/pgRouting.