You have several options for virtualization. If your needs are small and basic: VirtualBox/VMWare Player will do. You will need to re-install your server inside either of these solutions.
VMWare has software that could convert your current server into a virtual one, which can be used in VMWare only. If this software is able to convert your real server into a virtual one, make sure to test it first extensively before giving up the real server though.
Access times in a database can be affected by a lot of things. And what I have noticed with testing MS-SQL (2012) against Oracle (10g &11g & 12c) (each just using the most basic functionality) is that MS-SQL is slower. Sometimes significantly slower when you have created indexes that are filled by the DB software in a not so efficient way. To get that right, you need to have a deep insight in how MS-SQL does this and after you have fixed this yourself you'll need to be on the lookout for the DB not to mess it up again when it maintains these indexes. In this regard, Oracle is much more efficient and you see that back in improved access times.
So, if your DB relies a lot on indexes, getting these filled and maintained properly requires you to spend time keeping them in shape. Reducing the amount of indexes might help, but that usually leads to database (re-)design. Good database design is harder than it looks. Finding the balance between storing data into the database and getting this data into your application as fast as possible can be tricky.
There is software included with the MS-SQL Server 2012 Express installer, that shows you where the time is spent when you make a query against the database. I must say that this software is more intuitive than the software that comes with Oracle databases.
You can install this software by downloading the 1GByte+ MS-SQL 2012 Express installer and follow the installation instructions. You'll need to mark first that you want to install the complete package and after a while you are presented with an option screen where you disable whatever functionality you don't need. I just mention this, because it might be confusing at first.
It could be that this functionality is already available in MS-SQL 2008 Express. The only experience I have is with the MS-SQL 2012 database.
Anyway, the overview provided by this functionality will give you a clear insight in how to improve access times in your database. If the sole purpose of this exercise is to improve access times, that would be the first place I would look, instead of spending time to virtualize your whole setup and hope that this will bring the improvements you seek.