Read this
http://dottech.org/94596/windows-how-to-access-files-documents-data-when-windows-crash/edit:
https://multibit.org/en/help/v0.5/help_support_missingWallets.htmlUse your computer's search tool to find ".wallet" and include hidden directories - you should see the automatically generated backups. https://multibit.org/en/help/v0.5/help_troubleshooting.htmlWhere MultiBit stores your data
MultiBit stores user specific data such as logs and the
default multibit.wallet in a "user data directory". This directory can be worked out as follows:
1.Check the the very top of the "Messages" tab for a message like "The user data directory is '/Users/jim/
Library/Application Support/MultiBit'"
2.Navigate to the MultiBit installation directory and check for a file called "multibit.properties". If there is, use this directory as the user data directory. This is for backwards compatibility and for running everything from a USB drive.
3.If none of these reveal the answer, use the technical approach given below.
Technical approach
This section is for technical users proficient with accessing environment variables. These are enclosed in "[]" such that [APPDATA] references the APPDATA environment variable.
Windows
Try one of the following locations, remembering that you may need to enable hidden directories
[APPDATA]/MultiBit. Windows (7,8): C:\Documents and Settings\jim\AppData\Roaming\MultiBit
[APPDATA]/MultiBit. Windows (XP and below): C:\Documents and Settings\jim\Application Data\MultiBit
Ps: Try to unhide folders first, Maybe that wallet file is still thereOpen Folder option -> Click on "View" -> Select "Show hidden files,folders and drives"