It would have been best to ask us first before going off recklessly reinstalling Windows 7 assuming that it was the same as an XP Repair Install.
You say you have two installations on the HD now. How do you know this? Do you have a Dual Boot Menu?
You must have chosen Custom Install which gave you a selection of partitions - otherwise if you ran the installer from Windows 7 and chose Upgrade install it would have only done a Repair Install
which itself is a last resort, as we would have given you other repair steps first.
Post back a screenshot of your maximized Disk management drive map using the Snipping Tool in Start Menu and we will try to help you sort it out. Screen Shots
You can use the windows.old folder to roll back to the original installation if you overwrote it - but that's not certain if you now have two Windows 7 installations since one of them might be other old one if you chose another partition to reinstall upon. But if you have a windows.old folder chances are you did overwrite it so look over these steps: How to restore a Windows 7-based computer to a previous Windows installation by using the Windows.old folder
However this is complicated and by no means assured, so you might also decide to keep the fresh install, reinstall your programs and copy your files in from backup or windows.old.
We regularly solve problem here by having users uninstall any MucAfee product which is the worst crapware we see.
Use a free lightweight AV like Microsoft Security Essentials
with the Windows 7 firewall for best performance.