http://edhammond.blogspot.com/2010/07/removing-100mb-system-reserved.html

1. Open an administrative command prompt
2. Run bcdboot c:\windows /s c: and you should see Boot files successfully created
3. Open Disk Management (diskmgmt.msc)
4. Right-click the C:\ partition and select Mark Partition as Active
5. Reboot to confirm that everything is working
6. You can now delete the 100Mb System Reserved partition by right clicking on it and selecting Delete volume