Finding a Windows Partition on Ubuntu

Question

Good Evening All,

I've recently installed Ubuntu on an older laptop of mine. Originally I had thought that I completely overwrote the original OS, Windows 10, however when I had finished installing Ubuntu I downloaded sysinfo to check the system info and noticed that the total memory on the laptop seems to have reduced drastically. I've included the system profiler report on the memory below:

Memory
Memory
MemTotal           Total Memory 8064052 KiB
MemFree            Free Memory 4481184 KiB
MemAvailable       5975520 KiB
Buffers            88484 KiB
Cached             1671804 KiB
SwapCached         Cached Swap 0 KiB
Active             2093756 KiB
Inactive           1080904 KiB
Active(anon)       1415564 KiB
Inactive(anon)     90388 KiB
Active(file)       678192 KiB
Inactive(file)     990516 KiB
Unevictable        16 KiB
Mlocked            16 KiB
SwapTotal          Virtual Memory 2097148 KiB
SwapFree           Free Virtual Memory 2097148 KiB
Dirty              1284 KiB
Writeback          0 KiB
AnonPages          1414420 KiB
Mapped             510168 KiB
Shmem              91576 KiB
Slab               174044 KiB
SReclaimable       102924 KiB
SUnreclaim         71120 KiB
KernelStack        12768 KiB
PageTables         47672 KiB
NFS_Unstable       0 KiB
Bounce             0 KiB
WritebackTmp       0 KiB
CommitLimit        6129172 KiB
Committed_AS       6279400 KiB
VmallocTotal       -1 KiB
VmallocUsed        0 KiB
VmallocChunk       0 KiB
HardwareCorrupted  0 KiB
AnonHugePages      0 KiB
ShmemHugePages     0 KiB
ShmemPmdMapped     0 KiB
CmaTotal           0 KiB
CmaFree            0 KiB
HugePages_Total    0
HugePages_Free     0
HugePages_Rsvd     0
HugePages_Surp     0
Hugepagesize       2048 KiB
DirectMap4k        306060 KiB
DirectMap2M        4833280 KiB
DirectMap1G        4194304 KiB

When I tried to use the terminal to check for additional partitions I got the below results:

Device         Start       End   Sectors   Size Type  
/dev/sdb1       2048   1026047   1024000   500M EFI System  
/dev/sdb2    1026048   1288191    262144   128M Microsoft reserved  
/dev/sdb3    1288192 220254207 218966016 104.4G Microsoft basic data  
/dev/sdb4  220254208 221188095    933888   456M Windows recovery environment  
/dev/sdb5  221188096 247799807  26611712  12.7G Windows recovery environment  
/dev/sdb6  247799808 250030079   2230272   1.1G Windows recovery environment  

Apologies if this sounds obvious, but are those Windows partitions there? As I understand it the EFI system is Ubuntu, and the remainder of those are Windows partitions. I had thought that I'd removed Windows during the installation. If this is the case, how can I remove these partitions?

Any help would be greatly appreciated.

Cheers,

Scott