Are you willing to open up your computer?

I'm assuming both OS harddrives are in bootable condition.

What you want to do is change the boot order of the harddrives.

SATA: Swap the cables to the Windows 7 and the OS X harddrives (AT ONE END ONLY).
ATA: Reverse the master/slave settings. Either reverse the positions on the cable, or set the jumpers to force Master and Slave. If both are on two cables, see SATA

1 SATA/1 ATA: Annoying, but there HAS to be a way to change the boot order in your BIOS. Mine is kinda hidden and easy to miss.

Once OS X is the boot drive, you can install Chameleon

---

Tiger: G4 PowerPC Dual Core 400 Mhz w/640 MB RAM
20 Gig ATA HD all HFS+
Internal DVD
Access to Server
True Tiger

Leopard: Acer Intel Atom Dual [email protected] w/1 Gig Ram
160GB HD-133GB NTFS, 15.68GB HFS+
SD slot
No Net access
iDeneb 1.6 Lite

Compaq SR5710F [email protected] w/3 Gigs Ram
80 Gig ATA HD (NTFS - Vista)
200 Gig ATA HD (NTFS-Data)
Access to Server

Server: Compaq 1.8 Single Core Windows Server 2003 Enterprise Edition
~2 TB online....