So, if I install Airport Utility on my Windows 7 based Dell, I can access my backup files from my iMac within the time capsule's internal drive? Please answer if you know because I need to access these files and don't want to screw up my computer or TC.
Not easily. Time Machine backs up to a disk image called a sparsebundle. This is seen by Windows as an actual folder, with subsequent folders inside. I may be wrong, but I believe every time TM backs up to the Time Capsule, it creates a new one of these folders. You'll still be able to access the files within these folders, but as to which version a file is or where it is stored, it may prove to be a bit of a challenge to navigate.
If you need to access your files from your Mac on your Windows machine, it is best to mount the TC's HDD within OS X and copy the necessary files into a folder you create on the HDD.