Need to move .Net Assemblies to Program Files after Windows Update

I have a legacy windows client application that uses a several .Net assemblies (I created), one with a COM wrapper. The client application resides in a root drive subfolder (c:\somefolder...). Recently after a Windows update the application could not properly load the .Net assemblies. Prior to the update there were no issues.

I fixed the problem by movin开发者_运维问答g the assemblies to a subfolder under program files and re-registering (regasm) the COM assembly, then deleting the files from their existing location under the root drive. Although this works now, it is not a long term fix.

I have seen this problem after different windows updates so I can't pin it on a specific update. The problem shows up primarily on XP machines but have seen on Vista and 7. Any ideas about what may be occuring? Thanks.