phpinfo does not do anything for you, it only returns information about the server to the screen, information that you can use to trouble shoot problems on the server, or to find the location of the php.ini file that is being used when the server loads.
Is this error reported when testing the database connection?
If so, it means there is a problem in the site definition.
XAMPP Will have a different local root folder than MAMP did, usually it is c:\xampp\htdocs
make sure the local root in the Site definition settings is using the correct location, also in the testing server settings, make sure you are pointing to the correct location, and that you have the correct address entered for the URL Prefix.
As it says it is a 32 bit version ?
XAMPP runs fine in a 64 bit environment. Windows 7 64 Bit will still run 32 bit code, the 64 bit OS is backwards compatible.