***'cyclic redundancy check' and 'parameters incorrect'???***

Hey,I am really new to all of this and not a computer whizz...so i need help!!!
I have managed to download two roms for my R4 but when I try to copy them to the R4 folder (with the winrar prog) it comes up with either or the error messages detailed in this topic title..... I am so confused!!!!!Sophie

check your version of winrar is up to date. If it is, then delete the roms and redownload them. If not, update winrar.

Did loonys suggestiom work sophie ? i reccomend doing a disk check on your hdd anyway that crc error is a bother .

Ive had this problem before, it was just a bad download. Also I find it better to unzip to a folder and then drag the rom across seems to cause less problems.

Ah ok thank you everyone, I will try all of these tonight. My laptop is kinda old and ropey so that could be why!
It is soooo frustrating, i'm so near yeat so far!
I'll let you know what happens!
Sophie