what API can i use to determine the size of a certain file? thanks..
You can use GetFileSize, or GetFileInformationByHandle. Since you only want the file size, GetFileSize is probably the best option and also the easiest to get used to.
Both GetFileSize and GetFileInformationByHandle are good IF you already opened the file. If you don't want to open it just to check its size, use FindFirstFile
Have a look at the function in the MASM32 library called "filesize". It uses the FindFirstFile() function so you can either use it as is or have a look at it to see how its done. Regards, email@example.com