I have a client that has compressed their entire C drive. This drive contains SQL 2005 and IIS as well as Windows itself. Isn't this generally considered a bad idea? They use SQL for a large database application and they use IIS for hosing their on-line ordering system (just about to be released).Thank you!Chris

Yup, Generally.Especially if you are running a DB app.The problem is mainly performance.

Hi, Thank you for posting here. According to your description, I understand that you would like to know if its proper to compress Drive C:. If I have misunderstood the problem, please don't hesitate to let me know. As DJXMMX explained, the main problem is performance. NTFS compression has the following performance characteristics. When you copy or move a compressed NTFS file to a different folder, NTFS decompresses the file, copies or moves the file to the new location, and then recompresses the file. This behavior occurs even when the file is copied or moved between folders on the same computer. Compressed files are also expanded before copying over the network, so NTFS compression does not save network bandwidth. Because NTFS compression is processor-intensive, the performance cost is more noticeable on servers, which are frequently processor-bound. Heavily loaded servers with a lot of write traffic are poor candidates for data compression. However, you may not experience significant performance degradation with read-only, read-mostly, or lightly loaded servers. For more information, please refer to the following article. Best practices for NTFS compression in Windows http://support.microsoft.com/kb/251186 Thanks. This posting is provided "AS IS" with no warranties, and confers no rights.