Have a serious problem: Several large zipfiles give CRC errors when I unzip them or test them. Same with install from harddrive. I copied the installfiles of a program to harddrive because of a write error on the cd and same there: CRC errors. Some are able to proceed by choosing ´try again´. Strange thing is: when I abort and start install from scratch I also recieve CRCR errors but from different files. I´m getting the idea that there´s some sort of file transfer problem on my pc: I tried to burn a cd yesterday with Nero at 4 speed (to be on the safe side) and still had writinhg errors!!! Never happened before. So 1. What are CRC errors? 2. What can I do? Could it be insufficient power (have 230 volts), bad cables, wrong setup (harddrive as master and cd burner as slave on one IDE cable, dvd drive on second IDE cable). I´m getting frustrated here...

I don't know what the problem is, but you are not alone...here is an excerpt from a posting in 11/2000 on this subject...it won't point to the problem, but might have a solution: Name: WendellGee Date: November 19, 2000 at 19:26:11 Subject: CRC Errors on Dl's >10MB Reply: I was having problems with tons of CRC errors on zip files, and I found a solution that has worked every time I've tried it, without having to go to the trouble of downloading files over again. Head to http://www.fortunecity.co.uk/jodrellbank/galaxy/201/ (Fluxx's Freeware) and download a freeware utility listed there called "Zipfix." It's like the pkzipfix file that used to be included with PKZip, and so far it has successfully rebuilt any zip file I've had that had CRC errors, and without any loss of data. It also seems much more consistently useful than pkzipfix ever was; I haven't found a file yet that it didn't properly reconstruct. (Commendations to whoever wrote this godsend of a program. Who knew less than 100K of data would save me so much frustration? :) ) Hope this helps someone.

I forgot to mention this...if you are familiar with how zip files work, then you know that the crc is used to verify the data when it is un-zipped. There's only two points where the zip file corruption could occur...when the zip file is created or when the file is un-zipped. In your case, your CD-ROM appears to be involved...so, maybe your ROM is bad. I found where one individual who had the same problems with downloaded zip files resolved it by switching to a proxy server, his ISP was the culprit.

Thanks a lot. I´ll try that. I don´t think it will help me with the errors in the install files and burning acd though. I think I´m gonna buy new IDE cables and might by a 300 volts power. Any ideas on those problems?

Cyclic Redundancy Check - when the data is written, calculated codes are also written that allow the data to be checked for accuracy. When it is read, the codes are calculated and compared to those written. Any time there is a discrepancy, the data will not match the code. Errors can be caused by any of a number of things: (1) bad recording device, (2) bad medium, (3) bad read, (4) error in RAM, (5) m/b error, etc. Note that if you use a fix utility as suggested above, there is no guarantee that its output will be correct 100% of the time.