First, make sure you have SCAR 3.15 by downloading it at http://freddy1990.com/scar.php .
Next, download Subversion by Tigris at http://subversion.tigris.org/files/d....4.5-setup.exe .
Before running the installation for SCAR 3.15, right click SCAR315bSetup.exe and click Run as Administrator. If it asks for a password, and you don't know it, you're screwed. Else, allow it to access your computer.
Once it's installed, right click svn-1.4.5-setup.exe wherever you saved it, and click Run as Administrator. Same rules as above apply.
Once Subversion is installed, go to your desktop and right click SCAR 3.15. Click Run as Administrator. Once it is open, go to Tools -> Options... -> SRL Download, then highlight Subversion Repository. Then click checkout. Once the download is complete, hit ok.
Now, on the desktop right click SCAR 3.15. Click Properties...Then move to the Compatibility tab. At the bottom, select Run this program as Administrator. Then, hit ok!
Congratulations! You have very quickly installed SCAR/SRL on Vista