Assuming that your PC is "healthy" and its network adapter properly configured for your environment; the speed that you can download at then becomes dependent upon what network hardware i.e., servers, routers, switches, hubs, etc. your office is using, how that hardware is configured, and how much total bandwidth is available per the plan your office has with it's IP. It would help if you could describe the office network environment in detail, but I think you should actually address this problem with whoever is responsible for your office's network maintenance in order to avoid a possible conflict with company management policies.
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