This may be a separate issue, but I recently (after the fix) had a similar installation issue. The component installed ok, but when installing sample data this time the error was:
Warning: require_once(C:\wamp\www\tom_and_daves/administrator/components/com_virtuemart//sql/sql.virtuemart.php) [function.require-once]: failed to open stream: No such file or directory in C:\wamp\www\tom_and_daves\administrator\components\com_virtuemart\install.php on line 136
Fatal error: require_once() [function.require]: Failed opening required 'C:\wamp\www\tom_and_daves/administrator/components/com_virtuemart//sql/sql.virtuemart.php' (include_path='.;C:\php5\pear') in C:\wamp\www\tom_and_daves\administrator\components\com_virtuemart\install.php on line 136
After installing that build and getting the error VM wouldn't uninstall, so I manually cleaned the Database and VM files. Tried reinstalling, same thing. Tried an earlier build, also same. Had to do a fresh Joomla/VM install to fix.