ASPNET Worker Process Recycled?!

I received a ad-hoc task for retrieving, sorting and filtering data from a Excel file tonight, it's pretty simple and straighforward - Just use an appropriate connectionString in ADO.NET then I can connect to the 'data source' and manipulate the data directly.

However, I 'hang' for about 5 minutes in front of my workstation in the process! There're two problems which were sucking me:

1. A Excel worksheet was used as a Data Source by user, well, I understand this situation as users are more familiar with the Office products sense, but the point is that the single worksheet contain >= 20Mb of data, which take me l..o..n..g.. time in loading. 20Mb is a insignificant size when storing in a SQL Server, but loading up a 20Mb Excel file is really face a heavy performance penalty. (More info: The file is connected and filled with data from a SQL Server, but I'm not authorized to access to this Server directly, don't laugh at me)

2. An error message with something like "aspnet worker process recycled" displayed when I was retrieving the data from the 'data source'. Next, I go to open up my Event Viewer and see what's going on. The reason is something like "Insufficient memory - the ASP.NET process take > 60% of my physical memory". Ah.... I have 256Mb physical RAM in my workstation and... I don't want to waste time in this issue but just search and scan a similar Kb from Microsoft support site.

Finally, my solution is to break down the amount of data to be SELECT for retrival in order to 'avoid' this problem, I don't want to spend more time in investigating or trying to solve this problem tonight, as I want to completed my task ASAP and off - I've stayed in office for nearly 12 hours already.

Inproper way for problem-solving and learning? or reply to user in the shortest response time? Who win? Excel or XML or other Data Source will you suggest to users?