Problem with Windows invalid drive

"Invalid drive W:" was encountered during installation (there may be many cases of the letter). This is my ghost outfit Win7,

Encountered when installing JDK, this problem also causes word not to open the file normally, many software cannot install.

The solution is, first of all, Win7: Start Right-click the advanced system settings on the left of the computer properties

XP: Right-click the properties of my computer on the Desktop Advanced tab

Then, open "Environment variables", you should find the current user's environment variables in the TEMP and TMP two environment variables, the value is the error w:usertemp (depending on the circumstances), the system variable also has TEMP and TMP, the value is w:systemp.

Since W: does not exist, change it to one of your existing disks, such as C:usertemp and C:systemp.

Remember to change all two!