You are in need to Fix System Errors with Mac OS X Snow Leopard's but don't know how then here is the solution. The File system used by Mac OS X is hfs + and all the partition on the Mac hard drive should be in the same file system. It can be created by using the inbuilt disk utility. But there are certain circumstances like abrupt system shut down, hard drive error, partition failure and virus infection due to which the file system will get corrupt and you will not be able to access the content of the drive and the system will not boot. So you have to Fix System Errors with Mac OS X Snow Leopard's if you want to retrieve the important files. This can be done by using the disk utility which is able to find out minor problems and try to fix them but if it is unsuccessful then you have to format the drive with the same tool. After the formatting you have fix System Errors with Mac OS X Snow Leopard's and now to recover the data use Time machine backup. When the time machine fails only option is to use the Mac data recovery software which can restore every lost files in the Mac.