BUG #8583: I can't install this product

The following bug has been logged on the website:

Bug reference:      8583
Logged by:          Igor Gladchenko
Email address:      gladchenkoigor@hotmail.com
PostgreSQL version: 9.3.1
Operating system:   Windows XP SP3
Description:

 can't install this product. When I run setup I get the following message:
"There has been an error.
Unable to write inside the TEMP environment variable path".
I have the following environment variables: Temp=C:\Temp
Tmp=C:\Tmp.
What to do?