"There is not enough memory or disk space to run Word"

Today i have installed compatibility pack 2007 and since then when i am trying to open Microsoft Word then i am getting an error message saying "There is not enough memory or disk space to run Word" . I did not had any issue in running word previously, i think compatibility pack 2007 has messed up something but i am not able to find out exactly what. I have checked out disk space and i am having 20 gb space left in my system, i dont know why i am getting not enough memory error . Any help for fixing this issue will be appreciated.

I am aware of the error you are getting, in order to get rid of it you will have to delete below key
HKLM\Software\Microsoft\Windows\CurrentVersion\Installer\UserData\<SID of the affected user>
You can follow below steps for doing that.
Go to start > run > type "regedit" without quotes and click on ok.
Navigate to above registry key and delete it.
Make sure that you are backing up current registry to be at safer side, best of luck.

I was getting same error in my case and i had tried out number of solutions for getting rid of it. The only solution that helped me out was creating new account,copying everything from old user folder to new one and than deleting old folder. I am not sure if you might be having same case but if deleting registry as mentioned by Bighiller doesn't fix this error then you can try out what i did.

Deleting HKLM\Software\Microsoft\Windows\CurrentVersion\Installer\UserData\<SID of the affected user> worked for me!!!!