Having read/write access for your Mac partition on Windows will come in handy if your Hackintosh becomes unbootable, because you'll be able to boot into Windows to recover your files (and possibly fix your Hackintosh's boot problem). On top of that, it's simply convenient.
LATEST UPDATE (January 26, 2013): Added Apple's Boot Camp Drivers to the article.
Paragon HFS+ ($20)
Paragon HFS+ ($20) is a Windows application that mounts all of your Mac hard drives in Windows Explorer (a.k.a. My Computer) and gives you read and write access. There's a 10-day trial available. Paragon HFS+ runs in the background and automatically starts on bootup, so accessing your Mac drives will feel exactly like accessing normal Windows drives.
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Apple's Boot Camp software is designed to help you run Windows on real Macs. Among other things, Boot Camp includes built-in HFS+ drivers for Windows. These drivers will mount your Mac hard drives in Windows Explorer and give you read access (but no write access). If you don't need to write any files to your Mac hard drives, using them is a free and relatively pain-free solution.
While the HFS+ drivers are normally packaged as part of Apple's Boot Camp Assistant software, you can download them separately below.
DOWNLOAD: HFS Driver v.4.0.2.0
The above download is a ZIP file; open the file in Windows by double-clicking it. Once opened, double-click the "Add_AppleHFS.reg" file. This will add the Boot Camp drivers to your Windows registry.
NOTES:
- This method has only been confirmed to work with Windows 7 and Windows 8.
- You must uninstall Paragon HFS+ or MacDrive from your computer before installing Apple's HFS+ drivers.
- To uninstall Apple's HFS+ drivers, delete the two driver files from C:\Windows\System32\drivers. Restart your computer. Then, double-click on the "Remove_AppleHFS.reg" file to remove the drivers from your Windows registry.
SOURCE: Apple HFS+ Windows Driver (Download) [MacRumors]