Windows Live Writer is one of the most popular offline blogging software. This is rather unusual – with the exception of operating systems, most Microsoft products are either useless or have better competitors.
However, Windows Live Writer stands out as an exception. It is used by thousands of bloggers around the world. Being a Microsoft product, it uses the .Net framework cleverly and brings you some superb functionality. Notable features include offline editing and drafting, seamless integration into most blogging softwares (Blogger, WordPress, LiveJournal etc.).
WLW is still in beta, which creates some problems for users. An oft-told complaint is that WLW is a resource hog, often causing the system to hang/freeze. This is really irritating. If you have not set WLW to auto-save, you might lose your precious posts.
If you check the Task Manager, the Processes tab will reveal that svchost.exe process is using most of the CPU. This is because Live Writer tries to check for updates online. The solution is to disable the update.
To solve resource-hogging by Live Writer, just follow these easy steps:
- Click “Run…” on the Start menu.
- Type “cmd” and then click “Open” (this will open a Command Prompt windows).
- In the Command Prompt window type the following code:
net stop "Windows Live Setup Service"
Press return key.
sc config "WLSetupSvc" start= disabled
Press return key. - Close the Command Prompt window and any other applications in use.
- Restart your computer.
- Start Writer and use it as you would normally.
This should fix the problem. Atleast it worked for me 
If you have any problems implementing this fix, do let me know through comments.