Here is a video tutorial showing how to get updated steam client without any need to install the previous one and update it, this way you can get already updated steam client without having to update from old one.
Basically this video was made to resolve the steam update error, but it can also be used to get the latest steam, so don't go by the video title.
Download and install the steam client from here http://cdn.steampowered.com/download/SteamInstall.msi
After Installing it would have ran automatically and you got the error "Steam is temporarily unavailable, please try later...". Now, goto your steam directory (c:\program files(x86)\steam)
Delete Clientregistry.blob file
Download the new steam.exe file (the newer version that comes after update) and replace it with the already existing steam.exe file in steam folder.
Now I have uploaded the file to upload.com here http://uploading.com/files/aac62963/Steam.exe/. No need to worry, the file has been scanned at Virus Total so you can view the summary report. Its completely free of viruses or anything. Just an updated version of steam.exe.
Now just run steam.exe without any compatibilty mode or anything. It will start updating soon (after 1 minute, it wont show any error or anything, it will star updating steam platform files, and you will have your steam client ready to play your favourite games.