|wait, what? |
If you shared a file from your Win7 PC, and now cannot access it from your machine anymore, then it's no wonder that no one else can either.
Check the security and sharing permissions (If simple File sharing is disabled).
Also check to ensure that file and printer sharing are enabled on the machine.
IT Desktop & Network Consultant - MOS Master Certified, MCP, MCITP - Windows 7, CCNA Certificate Pending, A+, Network +