Assuming you're using Windows xp or 2000, make sure you have logged on as adminstrator.
If you've done so already, try deleting all the files in your Temp folder first, before trying another installation.
Log on as admininstrator. Then in My Computer, click Tools, Folder Options, View tab. Tick the option "Show hidden files and folders'. Click OK.
Then in My Computer, navigate to the Temp folder at C:\Documents and Settings\Owner\Local Settings\Temp
Double click the Temp folder. Click Edit, Select All, and delete all the files (files in the Temp folder are safe to delete). Then try another installation.
This relates only to the first error message.
Also have a look here click here