I have had numerous instances in the past where a cd or dvd would not work because of a CRC(Cyclic redundancy check) error.So i thought maybe i can give some tips to avoid this error as much as possible. You can skip the next para to directly go to the causes and remedies of crc! --> Basic crc explanation! First crc check error is due to the mismatch between checksums during data writing and data retrieval.To put it simply checksums are like a large binary value obtained by adding values of the data in cd or dvd.When the data is written to cd,dvd a checksum value is created.When this file is retrieved again later the checksum is verified with the old checksum to ensure no data is lost while retrieving. What causes crc error *Dirty or scratched cd,dvd are very much the cause for this error. *Not writing with proper settings. There are many more but these two are prominent ones and so i'll discuss them. :yup: Remedies for crc error ->It goes without saying that the disc of best quality will perform better at extreme conditions. ->If the cd,dvd is scratched or dirty it is better to clean with a piece of cotton first.Special cd,dvd cleaning fluids are available which can be made use of.While cleaning with cotton clean from inner ring to outer ring because if there is any scratch radially outward it wont affect much of the present data.You can use water to an extent but avoid using soap or other chemical substance as it can damage the surface of the cd,dvd. ->Try to store the discs in relatively clean places..With right ambient conditions!Avoid direct exposure of the disc to light(it will be written in the disc covers). ->There are many recovery software available specifically for this purpose but never had one worked completely for me.Anyway thats my case your experience may vary. ->The next part or the most important part(imo)is settings used while writing the cd or dvd. I extensively use nero 7.There is a adjust speed option which many people are not aware of.This can greatly reduce the chance of crc error popping up.In the window where you choose the name of the disk(Where the default would be 'My Disc')there will be small arrow pointing towards left(to the extreme left of the window).If you click it you would open up a box in which the default speed would be the maximum speed of that disc. The problem with maximum speed is while writing it has a higher chance of missing a segment of datum which causes crc error later.So it is always better to choose slower speeds like 4x,it will take longer time to write the data but it would be 99% error free. ->Another tip i can give you is simulate and verify data while writing.Yes i know it is painfully slow but the reward is error free write session.Simulation will try to write data virtually into a disc so as to check for errors before actual writing(this option is available at the speed choice box).Verification tests the written data for any errors. You may wonder why am i saying this when most of the data transfer happens from either a usb thumb drive or external hard disk.But hey games till date comes in either dvd or cd format.You may never know when you will need to use discs. Any correction,suggestions are most welcome. This guide is just a start to the crc error.Google is your friend. Until next time.