Please tell us exactly how you reinstalled the OS - step by step.
(I'm looking at screenshots of the install process so I can remember exactly what steps happen >.> I don't have perfect powers of recall although I can remember what options I chose).
I inserted the Windows 7 disk, turned off the PC, and started it up. It asked me to boot from CD/DVD, which I did. When it asked me my language settings, I left the first option as English, put the second option as English (New Zealand), put the third option as the Korean keyboard (I'm learning Korean). At the next screen, I hit Install Now. When it asked what installation options I wanted, I chose Custom. Now, I have several partitions and two hard drives; I selected the partition on my SSD which was the "old" (one week old) Windows 7 partition, as I wanted to replace that with a fresh copy of Windows 7.
Then it went on with the installation process. After restarting, I input my username, computer name, password, password hint, activation key, timezone, and set my network as Home network. For the Homegroup options, I deselected everything except Printing, if I recall correctly.
The first drivers I installed were the motherboard drivers included on a disk that came with the motherboard. I've had no troubles with those drivers on Win XP (what I am running on another partition). That got my internet connection up, so I downloaded Chrome and Skype (can't stand IE, and I had some Skype stuff I wanted to stay updated on). Then I finished installing my mouse driver, sound card driver, and download Catalyst Control Centre for my graphics card and installed that. Then I started installing StarCraft II (this is the main thing that finally made me reinstall; I could live with not accessing some Windows apps for some of the time, but I couldn't get SC2 to install properly and suspected that the Windows applications not starting was a related problem). The installation for StarCraft II didn't go any better than before I booted. I then checked to see if the Windows apps were actually fixed and to my dismay they weren't, so I came and started this thread. After that I installed all the updates available; no change occured in the hanging Windows apps though.