MSDE Database at 100%

By the sounds of it you have no free space in the database. You want 10% free and 90% used. If you are using Enterprise Manager you will want to optimize the database leaving 10% free.

I'm not sure the parameters used by the reindex feature in the Store Ops Admin program, but I would run it to see if that will give you that 10% growth space you need. (if you do not use Enterprise Manager)

In SO Administrator, connect to the database (File/Connect) Open a new query Window (Query/New) Enter the following query: EXEC sp_helpfile Run the query (Query/Run) You should get two rows in the results of this query - the first one represents your data file, the second represents your log file. Check the "Size", "maxsize" and "growth" columns. If the Maxsize is "Unlimited", the file should automatically grow until the available drive space is full. The file will grow by the % listed in the "growth" column.

How much free space do you have on the data drive(according to Windows Explorer)? If the drive is getting full, there may not be enough space for the file to auto grow. This will usually present itself as a error telling you there is no room to write a transaction rather than reduced speed.

Do you have backups scheduled during the day, or is it possible that other users are running reports or using SO Manager to update items?

If these occasional slowdowns are hurting your business, you should get your reseller in to take a look. From what you've posted, I don't think that the basic SQL/MSDE setup is your problem, unless you are doing 100 MB worth of transactions per day ( the next time your DB autogrows, it's going to grow by 94MB...). More likely issues are unusual user activities during those times, like reports, searching customer or Item lists, or anything else that might pull a large block of data from the DB. You might want to check your disk for fragmentation though.