Unable To Install Error

I tried to play GW today but it wont startup

I started the game and it updated something then on the next screen a different window to the one im used to (its the one when ur first installing the game) came up with the arenanet logo in the right corner and it says downloading..
After a second or 2 i get this message

Unable to Install

The installer could not write Guild Wars to the specified directory. Check admin privelidges, permission to install and space.

Now ive previously installed and played and it was fine. My account is admin and i have 11 gb left on the partition that GW is on. So i dont kno whats wrong.

Ive tried reinstalling the game, same thing. Removed the dat file and it downloaded something on startup and then the same prob. Removed the tmp file same prob.

Any ideas?

Im getting the same problem, this sucks.

hmm.. i got this from playNC:

aint got time to do it at the mo, if anyone does have this prob and tries their solution let me kno if it worked..

Personally i dont think it will because it worked from the program files folder before perfectly but today it refuses.. when ive finished this assignment ill give it a try aswell

It does sound like you have to uninstall then re-install but... GW is not in the "My Documents" folder ><

or try altering the gw.exe shortcut and add -repair and see if it helps.