The installation on Windows 7 X64 isn't as simple as running the setup from the trial version. I have a detailed walkthrough on my site of how to install SharePoint on Windows 7. You can find it here:
http://www.dontpapanic.com/blog/?p=96
Having Office 2007 installed on the PC shouldn't cause an issue.
Paul Stork SharePoint Server
MVP Senior Solutions Architect: BlueChip Consulting Group
Blog: http://dontpapanic.com/blog
Twitter: Follow @pstork
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