You're not doing anything wrong, val ... the PC's being a beast.
"Error 1310. Error writing to file: C:\Program Files\Windows Installer Clean up\msicuu.exe. Verify that you have access to that directory."
Strange messages questioning your permissions (that don't seem to respond to ownership) and now an installation error message down in the low 1300s ... we'd better stop and do a disk check on your C drive. This has a bit of a scent of disk/file damage to it.
Restart the PC and don't launch any applications. Now go "Start > Computer" Right-click your C drive and select "Properties". Click the Tools tab, and in the "Error checking" area of the tab, click "Check now". The disk check may take a wee while.
Does it find/repair any damage?